Socket assembly

ABSTRACT

A socket assembly for accommodating an IC chip or package (IC) provided with a socket body having a generally rectangular configuration. A plurality of flat plate-like contact pins are arranged forming rows in parallel with each other so as to form rows along four sides of the socket body, respectively. Each contact pin has a base portion and an arm which extends curved upward from the base portion. An upward contact portion for coming into contact with a terminal of an IC is formed on one end of the base portion of the contact pin, and a connecting portion for the connection to the printed circuit board is formed on the other end of the base portion. Four sliders are arranged along the four sides of the socket body, respectively. Each slider is supported by the base portions and arms of the row-forming contact pins and can move between an open position for accommodating the IC and a pressing position for pressing against the IC by an elastic force of the arms to bring the terminals of the IC into press-contact with the contact portions of the contact pins.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an improved socket assembly foraccommodating an electronic or electrical component such as anintegrated circuit chip or a package (IC) or a chip-on-board module etc.and for electrically connecting an electrical component to a printedcircuit board.

2. Description of the Related Art

In general, an electronic or electrical component such as an integratedcircuit chip or package (IC) or a chip-on-board module etc. is connectedand affixed by directly soldering terminals such as leads or padsarranged along the sides of the electrical component onto the printedcircuit board. On the other hand, where it is mounted on a printedcircuit board for testing or the like in a manner enabling theelectrical component to be easily replaced or where an electricalcomponent in which the heat caused when soldering is liable to exert anadverse influence upon the internal circuits is mounted on a printedcircuit board etc., generally use is made of a socket of a top loadingtype to accommodate the electrical component. As disclosed in JapaneseUnexamined Patent Publication (Kokai) No. 64-3977 and JapaneseUnexamined Patent Publication (Kokai) No. 2-51882, a conventionaltypical top load socket is provided with a generally rectangularconfiguration support frame or socket body made of a plastic. The socketbody has a plurality of contact pins disposed in a row in parallel oneach of the sides thereof. Each contact pin is provided with an externalconnecting portion for connection to a conductor pattern on the printedcircuit board and a contact portion for coming into contact with aterminal of the electrical component. The socket body is furtherprovided with a cap or a cover pressing against an upper surface of theelectrical component mounted on the contact portions of the contact pinsand an engagement piece for engaging the cover with the socket body at aposition where the cover presses against the upper surface of theelectrical component. The row-forming contact pins are defined in theirintervals by partition walls or ribs provided in a row in parallel onthe socket body. Further, the contact portions of the contact pins passthrough a base plate of the socket body disposed on the printed circuitboard and project beneath the same.

In the above-mentioned conventional socket, all terminals of theelectrical component and all contact portions of all contact pins on thesocket body are simultaneously brought into press-contact with eachother by the pressing force of the cover and therefore when the numberof the contact pins is increased, a very large pressing force becomesnecessary so as to give a required contact pressure to the contactportions of the contact pins. Accordingly, an operation such asattachment, engagement, etc. of the cover becomes difficult.Accordingly, it is difficult to deal with higher density terminals in anelectrical component such as an IC. Also, the electrical component ispressed from the top by a large force, and therefore this has become acause of causing excessive stress in the electrical component or socketbody. Also, if the strength of the socket body or cover is notsufficient, warping is produced in them, and as a result, the contactpressure of the contact pins becomes small, which becomes a cause ofinducing poor contact. Particularly, in a high temperature environment,the plastic of the socket body undergoes stress relaxation, whichfurther increases the warping.

Further, in the above-mentioned conventional socket, since the terminalsof the electrical component and the contact portions of the contact pinsare electrically connected by the contact pressure, poor conduction isapt to occur due to dirt, oxide film, etc. deposited on the terminals orcontact portions. Accordingly, desirably, when the terminals of theelectrical component come into contact with the contact portions of thecontact pins, they should cause a so-called wiping action to remove thedirt, oxide film, etc. In the above-mentioned conventional socket,however, the electrical component positioned by the socket body ispressed in its thickness direction by the cover, and therefore it isdifficult for a wiping action to occur between the electrical componentand contact pins. Accordingly, it is difficult to enhance thereliability of the electrical connection between the electricalcomponent and the contact pins.

A top load socket disclosed in U.S. Pat. No. 4,993,955 is provided witha plurality of contact pins arranged so as to form rows in parallelrespectively along the sides of the support frame or the socket body andcams arranged along the sides of the socket body. Each contact pin has acurved arm portion and a contact portion formed at the free end of thearm portion for coming into contact with the upper surface of a terminalof the IC. In this socket, the contact pin can be operated by a cam foreach row. However, the contact portions of the contact pins are broughtinto press-contact with the upper surface of the terminals of the IC dueto the elastic force of the contact pins, and therefore the contactpressure between the contact portions of the contact pins and the ICdepends on the spring constant of the contact pins. Also, since thecontact pins press against the terminals of the IC from the top, hardlyany wiping action occurs between the contact portions of the contactpins and the terminals of the IC.

Further, in the above-mentioned conventional socket, the partition wallsor ribs defining the intervals in the row-forming contact pins areprovided in the socket body so as to be aligned in a row. In this case,so as to reduce the pitch of the contact pins, it is necessary to usethin ribs. However, if the ribs are made thin, the strength thereof islowered, and the shaping becomes difficult. Accordingly, there is alimit to making the pitch of the contact pins narrower.

Further, in the above-mentioned conventional socket, the socket body isplaced on the printed circuit board and sandwiched between a part of thecontact pins and the printed circuit board, and therefore in a statewhere the contact pins are soldered on the printed circuit board, thesocket body cannot be detached from the printed circuit board. Also, thecontact portions of the contact pins are positioned above the base plateof the socket body and the electrical component is mounted on thecontact portions of the contact pins. Accordingly, there is a limit insuppression of the height of the electrical component mounted on theprinted circuit board via the socket.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a socket assembly whichenables easy attachment and detachment of an electrical componentwithout application of excessive stress to the electrical component orthe printed circuit board and, in addition, can prevent variations inthe electrical connection with the terminals of the electricalcomponent.

Another object of the present invention is to provide a socket assemblywhich can ensure the electrical connection with the terminals of theelectrical component.

Still another object of the present invention is to provide a socketassembly which can deal with the reduction of the terminal pitch of anelectrical component.

A further object of the present invention is to provide a light weightand thin socket assembly.

According to the present invention, there is provided a socket assemblyfor accommodating an electrical component having a plurality ofterminals and for electrically connecting the said electrical componentto a printed circuit board, comprising:

a socket body having a generally rectangular configuration;

a plurality of flat plate-like contact pins which are arranged formingrows in parallel respectively along at least opposite sides of the saidsocket body, each of the said contact pins having a base portion and anarm which extends curved upward from the said base portion, the saidbase portion having at one end thereof an upward contact portion forcontact to a terminal of the said electrical component and at the otherend thereof a connecting portion for connection to the said printedcircuit board; and

a plurality of sliders each of which is supported by the said baseportions and the said arms of the said row-forming contact pins and ismovable between an open position for accommodating the said electricalcomponent and a pressing position for pressing against the saidelectrical component by an elastic force of the said arms to bring theterminals of the said electrical component into contact with the saidcontact portions of the said contact pins.

In a socket assembly having the above-described configuration, after theelectrical component is mounted on the contact portions of the contactpins, the sliders are moved from the respective open positions to thepressing positions, whereby at least opposite sides of the electricalcomponent can be individually brought into press-contact with thecontact portions of the contact pins. Accordingly, it is not necessaryfor one slider to ensure a pressing force enough to bring all terminalsof the electrical component into contact with the contact portions ofall contact pins by a required contact pressure. It is enough so far asit is a pressing force that can bring a row of terminals of theelectrical component and the contact portions of a row of contact pinsinto contact with each other by a required contact pressure.Accordingly, it is possible to reduce the force necessary for themovement of the respective sliders, and therefore the attachment anddetachment work of the electrical component becomes easy. Also, theelectrical component is pressed by the sliders by the elastic force ofthe arms of the contact pins in the rows, and therefore even if there isa variation in the spring force of arms of the contact pins, the contactportions of the contact pins in the rows and the terminals of theelectrical component will come into contact with each other by a uniformcontact pressure.

Preferably, the slider has an upper surface pressing portion pressingagainst an upper surface of the electrical component and a side surfacepressing portion pressing against a side surface of the electricalcomponent. In this structure, the slider presses against the uppersurface and side surface of the electrical component at the pressingposition, and therefore it is possible to reliably produce a wipingaction between the terminals of the electrical component and the contactportions of the contact pins by moving at least two sliders arranged onthe opposite sides of the socket body in order from the open position tothe pressing position. Accordingly, electrical connection between thecontact pins and electrical component becomes reliable.

Further preferably, a plurality of ribs which are slidably fittedbetween the arms and the base portions of the contact pins in the roware formed on the upper surfaces and lower surfaces of the sliders.

It is also possible even if the socket body has a jig guide means whichis engaged with the opposite end portions of the sliders and guides ajig for moving the sliders between the open position and the pressingposition in a vertical direction. In this case, preferably the jig guidemeans has guide holes at four corners of the socket body and guidegroove holes which are adjacent to the guide holes and formed along theopposite ends of the rows of the contact pins, pins positioned above theguide groove holes are provided at both ends of the sliders, and the jighas guide posts inserted into the guide holes and leg portions insertedinto the guide groove holes, and inward or outward inclined surfaces areformed at the tips of the leg portions.

Further preferably, a plurality of ribs respectively fitted between thebase portions of the row of the contact pins are formed on at leastopposite sides of the socket body so as to form rows.

Further preferably, engagement grooves extending along the rows of thecontact pins are formed in the at least opposite sides of the socketbody and projection portions engaged with the engagement grooves areformed at the base portions of the rows of the said contact pins.

Also, according to the present invention, there is provided a socketassembly for accommodating an electrical component having a plurality ofterminals and for electrically connecting the said electrical componentto a printed circuit board, comprising:

a socket body having a generally rectangular configuration;

a plurality of flat plate-like contact pins which are arranged formingrows in parallel respectively along at least opposite sides of the saidsocket body, each of the said contact pins having a base portion and anarm which extends curved upward from the said base portion, the saidbase portion having at one end thereof an upward contact portion forcontact to a terminal of the said electrical component and at the otherend thereof a connecting portion for connection to the said printedcircuit board; and

a plurality of sliders which are respectively arranged along the said atleast opposite sides of the said socket body, wherein each of the saidslides has a movable member which is positioned on an upper side betweenthe said base portions and the said arms of the said row-forming contactpins and which is movable between an open position for accommodating thesaid electrical component and a pressing position for pressing againstthe said electrical component by the elastic force of the said arms tobring the terminals of the said electrical component into press-contactwith the said contact portions of the said contact pins, a stationarymember which is positioned on an upper side between the said baseportions and the said arms of the said row of contact pins and fixed onthe said lower arms, and a driving member which is engaged with opposingsurfaces of the said movable member and the said stationary member, thesaid driving member being rotatable to move the said movable memberbetween the said open position and the said pressing position.

In the socket assembly having the above-described configuration, themovable member of the slider can be moved to the open position or thepressing position by pivoting the driving member of the slider.

Preferably, the stationary member of the slider has an upper surfacepressing portion for pressing against an upper surface of the electricalcomponent and a side surface pressing portion for pressing against aside surface of the electrical component.

Further preferably, the stationary member of the slider has an uppersurface which comes into sliding contact with the arms of the row ofcontact pins and a lower surface which comes into sliding contact withthe base portions, and a plurality of ribs which are respectivelyslidably fitted between the arms of the row of contact pins are formedon the upper surface of the stationary member so as to form a row.

Further preferably, a lever for pivotally operating the drive pinion isprovided on both end portions of the driving member.

Further preferably, the driving member is a pinion engaging with racksformed on the opposing surfaces of the movable member and the stationarymember.

Also, according to the present invention, there is provided a socketassembly for accommodating an electrical component having a plurality ofterminals and for electrically connecting the said electrical componentto a printed circuit board, comprising:

a socket body having a generally rectangular configuration;

a plurality of flat plate-like contact pins which are arranged formingrows in parallel respectively along at least opposite sides of the saidsocket body, each of the said contact pins having a base portion and anarm which extends curved upward from the said base portion, the saidbase portion having at one end thereof an upward contact portion forcontact to a terminal of the said electrical component and at the otherend thereof a connecting portion for connection to the said printedcircuit board; and

a plurality of sliders each of which is supported by the said baseportions and the said arms of the said contact pins forming a row and ismovable between an open position for accommodating the said electricalcomponent and a pressing position for pressing against the saidelectrical component by an elastic force of the said arms to bring theterminals of the said electrical component into contact with the saidcontact portions of the said contact pins,

wherein each slider has one end portion pressing against the electricalcomponent and another end portion on an opposite side to the one endportion, a plurality of arm insertion holes for accommodating tipportions of the said arms of the said row-forming contact pins areformed on the said another end portion of the said slider, and the uppersurface of the said slider covers the said arms of the said row-formingcontact pins.

In the socket assembly having the above-described configuration, theslider is held by the arms so as to cover the upper surfaces of the armsof the row of contact pins, and therefore the slider is useful as acover for protection of the upper surfaces of the contact pins. Also, itis possible to directly operate the slider from the top of the arms toeasily slide the slider, and therefore a jig or an operating mechanismfor performing the sliding operation of the slider from an externalportion becomes unnecessary. Accordingly, the configuration of thesocket assembly can be simplified.

Preferably, recesses for lowering the slider reaching near the pressingposition are formed in the upper surfaces of the base portions in thevicinity of the contact portions of the contact pins, and the tipportions of the arms of the contact pins extend inclined toward thecontact portions so that the spring force given to the slider isincreased as the slider approaches the recesses.

Further preferably, a notch for abutting against the side surface andthe upper surface of the electrical component is formed in one endportion of the slider.

Further preferably, the slider has an upper thick portion along theupper surfaces of the tip portions of the arms of the contact pins and alower thick portion along the lower surfaces of the arms, the upperthick portion of the slider extends longer than the lower thick portionof the slider toward the other end portion side of the slider, insertionholes for the arms of the slider are opened in the end surface of thelower thick portion of the slider, and arm guide grooves continuing withthe respective arm insertion holes are formed in the lower surface ofthe upper thick portion of the slider.

Further preferably, the slider has a slide contact portion projectingfrom the lower surface of one end portion thereof, and only the slidecontact portion of the slider comes into sliding contact with the uppersurface of the base portions of the contact pins.

Further preferably, guide ribs slidably engaged between the baseportions of a row of contact pins are formed on and projected from thelower surface of the slider.

Also, according to the present invention, there is provided a socketassembly for accommodating an electrical component having a plurality ofterminals and for electrically connecting the said electrical componentto a printed circuit board, comprising:

a socket body having a generally rectangular configuration; and

a plurality of flat plate-like contact pins which are arranged forming arow in parallel along at least one side of the said socket body, each ofthe said contact pins having a base portion and a leg portion projecteddownward from the said base portion, the said base portion having at oneend thereof an upward contact portion for contact to a terminal of thesaid electrical component and also having at the other end thereof aconnecting portion for connection to the said printed circuit board,

wherein two rows of slits into which the said leg portions of the saidrow of contact pins are inserted are arranged in a zigzag manner in thesaid socket body, first ribs for defining the intervals of contact pinsinserted into one of the rows of the said slits and second ribs fordefining the interval of the contact pins inserted into the said slitswhich form the other row are alternately arranged in a zigzag manner soas to form two rows, and contact pins inserted into the said slitsforming the other row are disposed on the said first ribs.

As mentioned above, by dividing ribs for preventing the contact betweenthe contact pins and adjoining contact pins into two groups andalternately arranging the contact pins and ribs of the respectivegroups, it is possible to reduce the pitch of the contact pins to a halfof the pitch of the ribs.

Preferably, the first and second ribs are arranged in the vicinity ofthe contact portions of the contact pins in the row.

Further preferably, each of the contact pins has an arm which extendscurved upward from the base portion, and the slider is supported by thebase portions of the said row of contact pins and the arms and ismovable between an open position for accommodating the electricalcomponent and a pressing position for pressing against the upper surfaceand the side surface of the electrical component by the elastic force ofthe arms and bringing the terminals of the electrical component intopress-contact with the contact portions of the contact pins.

It is also possible for the socket assembly to provide a pressing capwhich is detachably engaged with the socket body so as to press againstthe upper surface of the electrical component to bring the terminals ofthe electrical component into press-contact with the contact portions ofthe contact pins.

Also, according to the present invention, there is provided a socketassembly for accommodating an electrical component having a plurality ofterminals and for electrically connecting the electrical component to aprinted circuit board, comprising:

a socket body;

a plurality of contact pins which are implanted on the said socket bodyand arranged forming a row in parallel along at least one side of thesaid socket body, each of the said contact pins having a contact portionfor the contact with a terminal of the said electrical component;

a slider which is arranged along at least one side of the said socketbody and movable between the open position for accommodating the saidelectrical component and the pressing position for pressing against thesaid electrical component to bring the terminals of the said electricalcomponent into press-contact with the said contact portions of the saidcontact pins; and

a spring means which is arranged along at least one side of the saidsocket body and gives a pressing force with respect to the saidelectrical component to the said slider,

wherein the said row-forming contact pins have bent portions projectedto one side thereof, the said slider has a pressing portion for pressingagainst an upper surface of the said electrical component and aplurality of engagement members engageable with the said bent portions,and the said engagement members are adapted to pass the said bentportions while resiliently displacing the said contact pins laterallyduring a period when the pressing portion of the said slider furtheradvances along the upper surface of the electrical component afterreaching the upper surface of the electrical component from the openposition at which it retracts from the upper surface of the electricalcomponent, whereby the said contact portions of the said contact pinsare slid with respect to the said terminals of the said electricalcomponent.

In the socket assembly having the above-described configuration, afterthe electrical component is mounted on the socket body and the terminalsof the electrical component are brought into contact with the top of thecontact portions of the contact pins, the sliders are moved from theopen position and the pressing portions thereof are brought intopress-contact with the upper surface of the electrical component by thespring force of the spring means, whereby it is possible to hold andsecure the electrical component by the contact pins and the sliders and,at the same time, electrically bring the terminals of the electricalcomponent into contact with the contact portions of the contact pins bya desired contact pressure. In this case, the vicinity of the top edgeof the electrical component is held and secured by the contact pins andthe sliders, and therefore it is possible to prevent an undesirablestress other than the compression stress in the vertical thicknessdirection, for example a bent moment etc. from acting upon theelectrical component, and damage of the electrical component due tothese undesirable stresses can be prevented.

In addition, bent portions projected to one side of the contact pins areprovided in a part of the respective contact pins, a plurality ofengagement members engageable with the bent portions of the contact pinsare provided in the sliders, and the engagement members pass through thebent portions while resiliently displacing the contact pins to the sideduring a period when the pressing portions of the sliders furtheradvance along the upper surface of the electrical component afterreaching the upper surface of the electrical component from the openposition, and therefore it is possible to produce a wiping action in adirection substantially orthogonal to the movement direction of thesliders (horizontal direction) between the contact portions of thecontact pins and the terminals of the electrical component under adesired contact pressure during a period when the engagement memberpasses through the bent portions. This wiping can be reliably executedby a stroke determined in advance irrespective of the degree of standarddifference of positioning of the electrical component with respect tothe socket body, and therefore an electrical connection having a highreliability can be realized between the terminals of the electricalcomponent and the contact portions of the contact pins.

Also, when the slider returns from the pressing position to the openposition, the bent portions of the contact pins abut against theengagement members of the slider, thereby to serve in the role of astopper with respect to the return thereof, and therefore it is possibleto prevent the electrical component from carelessly being dropped fromthe socket body.

Preferably, the engagement members of the socket are arranged onopposite side surfaces of each aforesaid contact pin.

Further preferably, the bent portions of the contact pins arealternately projected in opposing directions in the order of arrangementof the contact pins.

Further preferably, each aforesaid contact pin is provided with asupport portion extended downward from a space between the contactportion and the bent portion and the lower end portion of the same issupported by the socket body.

Also, according to the present invention, there is provided a socketassembly for accommodating an electrical component having a plurality ofterminals and for electrically connecting the said electrical componentto a printed circuit board, comprising:

a socket body having a generally rectangular configuration;

a plurality of flat plate-like contact pins which are arranged formingrows in parallel respectively along at least opposite sides of the saidsocket body, each of the said contact pins having a base portion and anarm which extends curved upward from the said base portion, the saidbase portion having at one end thereof an upward contact portion forcontact to a terminal of the said electrical component and at the otherend thereof a connecting portion for connection to the said printedcircuit board; and

pivot cams, each of which is supported by tip portions of the said armsof the said row-forming contact pins and which can pivot between aposition of a standing state and a position of a substantiallyhorizontal state, wherein each of the said pivot cams retracts from aninsertion region for the said electrical component in the standing stateand presses against the said electrical component by an elastic force ofthe said arms of the said contact pins in the horizontal state to bringthe said terminals of the said electrical component into contact withthe said contact portions of the said row-forming contact pins.

Preferably, each of the pivot cams has a standing contact portion whichcomes into contact with the upper surfaces of the base portions of thecontact pins at the time of the standing state described before and ahorizontal contact portion which comes into contact with the uppersurfaces of the base portions of the contact pins at the time of thesubstantially horizontal state described before, the elastic force ofthe arms of the contact pins is imparted to the slider from the tipportions of the arms in a direction substantially perpendicular to thestanding contact portion, and a distance from the horizontal contactportion to the electrical component is larger than the distance from thetip portion of the arms to the electrical component.

Further preferably, an extension piece for pivoting the pivot cam isprovided in the pivot cam.

Also, according to the present invention, there is provided a socketassembly for accommodating an electrical component having a plurality ofterminals and for electrically connecting the electrical component to aconductor pattern on a printed circuit board, comprising:

a support frame having a generally rectangular configuration whichsurrounds the periphery of the said electrical component;

a plurality of flat plate-like contact pins which are arranged formingrows in parallel respectively along at least opposite sides of the saidsocket body, each of the said contact pins having a base portion and anarm which extends curved upward from the base portion, the said baseportion having at one end thereof an upward contact portion for contactto the terminals of the said electrical component and at the other endthereof a connecting portion for connection to the said conductorpattern of the said printed circuit board; and

a plurality of sliders each of which is supported by the said baseportions and the said arms of the said row-forming contact pins and ismovable between an open position for accommodating the said electricalcomponent and a pressing position for pressing against the saidelectrical component by an elastic force of the said arms to bring theterminals of the said electrical component into contact with the saidcontact portions of the said contact pins,

wherein the said contact pins are detachably engaged with the saidsupport frame so that after the said connecting portions of the saidcontact pins are connected and secured to the said conductor pattern ofthe said printed circuit board by solderings, the said support frame canbe detached from the said contact pins.

In the socket assembly having the above-described configuration, thecontact pins are detachably engaged with the support frame so that thesupport frame can be detached from the contact pins after the externalconnecting portions of the contact pins are secured to the conductorpattern of the printed circuit board by soldering, and therefore themounting height of the contact pins per se with respect to the circuitboard becomes small, and the mounting height of the electrical componentmounted on the contact pins with respect to the circuit board can bemade small. Further, since the support frame may be detached from thecontact pins according to need after the external connecting portions ofthe contact pins are secured to the conductor pattern of the printedcircuit board by soldering, it is possible to realize a light weightmounting construction of the electrical component. In addition, thecontact pins in the rows are soldered to the circuit board in a statewhere they are supported by the support frame, and therefore it ispossible to prevent the lowering of the efficiency of the soldering workand the positional precision of the contact pins with respect to theprinted circuit board.

Preferably, a plurality of ribs are provided inside and outside of thesupport frame so as to form rows, and the contact pins in the rows aredetachably engaged between the adjoining ribs inside and outside thesupport frame.

Further preferably, an upper cap covering the upper surface of theelectrical component is detachably attached to the support frame or anupper cap covering the upper surface of the electrical component isintegrally provided with the support frame. In this case, ribs definingthe intervals of the arms of the contact pins in the rows and an openingportion for visually confirming the contact portions of the contact pinsfrom above are formed.

Further preferably, with respect to the circuit board, the upper surfaceof the support frame has the same height as that of the contact pins ora lower height than that of the contact pins.

Further preferably, the contact pins in the rows are arranged in arectangular configuration and the sliders held by the contact pins inthe rows are formed so that the end portions abut against each other atthe pressing position.

Further preferably, partition walls for defining the intervals of thecontact pins in the row are formed in the sliders. In this case,preferably, the sliders are formed by a substance having a bad wettingproperty with respect to solder, and at least one part of the partitionwalls of the sliders is formed so as to cover a section positioned abovethe soldering section among the sliding regions of the contact pins withrespect to the partition walls of the sliders. It is also possible evenif the section positioned above the soldering section among the slidingregions of the contact pins sliding along the partition walls of thesliders is covered by a substance having a bad wetting property withrespect to solder.

Further preferably, at least one part of the pitch and width of theexternal connecting portions of the contact pins in the rows is madelarger than the pitch and width of the contact portions, respectively.

Further preferably, the contact pins of the respective rows are formedby simultaneous punching and simultaneous bending of one conductiveplate.

Also, according to the present invention, there is provided a socketassembly comprising a plurality of contact pins each of which has at oneend thereof an external connecting terminal and at the other end thereofa contact portion which can come into contact with a terminal of anelectrical component at the time of attachment of the electricalcomponent, and between them, is formed with a first spring portionbeside the said external connecting terminal and a second spring portionbeside the said contact portion, the said contact pins being disposed inparallel on a base plate while mutually insulated from each other, and

a slide member which has a first position defining portion and a secondposition defining portion which are respectively brought into contactwith the said first spring portion at a detachable position and aloading position for the said electrical component and receiving aposition restriction by its urging force and has an engagement portionwhich moves the said contact portion to the said detachable position bypushing the said second spring portion toward the first spring portionfrom its elastic neutral position.

Preferably, the urging force of the first spring portion acts in asubstantially vertical direction of the attached aforesaid electricalcomponent, and the urging force of the second spring portion acts in asubstantially side surface direction of the attached aforesaidelectrical component. Also, at the time of attachment of the electricalcomponent, the engagement portion pushes the second spring portions fromthe neutral position to a second direction, whereby the contact portionscome into sliding contact with the terminals of the electricalcomponent.

Further preferably, the structure is made so that, at the time ofattachment of the electrical component, a slide member can push the sidesurface of the electrical component.

Further preferably, the slide portion is held from the verticaldirection by an extension portion extended from between the externalconnecting terminals and the first spring portions and the first springportions so that it can move to the side.

Further preferably, at the loading position of the electrical component,the electrical component is held from the vertical direction by thecontact portions and the tip portions of the extension portions, and atleast one of the contact portions and the tip portions is used aselectrically conductive terminals with the electrical component.

Further preferably, in the slide member, engagement and contact portionsare provided on both end portions in a direction orthogonal to itsmovement direction, and the slide member is moved by an external devicevia the engagement and contact portions.

Further preferably, a plurality of ribs are disposed in parallel on theslide member, and the contact pins in the rows are isolated from eachother by the ribs.

In the socket assembly having the above-described configuration, whenthe slide members are moved to the outside in the horizontal directionof the socket using a jig etc., the engagement portions of the slidemembers warp the second spring portions of the contact pins and make thecontact portions of the contact pins retract to the side, thereby toenable the accommodation of the electrical component. The slide membersare positioned at that position by the urging force of the first springportions of the contact pins. When the electrical component is placed inthe accommodating portion in this state and the slide members are movedinward in the horizontal direction, the engagement portions of thecontact pins restore the second spring portions to the neutralpositions, so that the contact portions of the contact pins push againstthe electrical component from above and, at the same time, come intocontact with the terminals of the electrical component. The slidemembers are held in this state by the first spring portions. In a finalstage of the attachment action of the electrical component, theengagement portions enable a further pushing of the second springportions from the neutral position in the same direction, or the slidermembers push against the side surfaces of the electrical component,whereby wiping between the terminals of the electrical component and thecontact portions of the contact pins is carried out and the conductivitycan be improved. Also, extension portions are provided in a spacebetween the same and the external connecting terminals of the contactpin, and the electrical component is held by the contact portions andthe extension portions, whereby it becomes possible to apply the samealso to electrical components having terminals provided on the uppersurface side thereof or electrical components having terminals providedon the lower surface side.

Also, according to the present invention, there is provided a socketassembly comprising: a plurality of contact pins arranged in parallel onabase plate in such a manner that a spring portion is formed between acontact portion that can come into contact with a terminal of a loadedelectrical component and an external connecting terminal and anengagement portion is formed between the said contact portion and thesaid spring portion; and an actuation shaft member arranged along theparallel arrangement direction of the said contact pins and given arotation force by a spring member, the said actuation shaft memberhaving an arm at at least one end thereof and being formed at acircumferential surface thereof with engagement portions which areengaged with the engagement portions of the said respective contactpins, wherein either one of the engagement portion of the said contactpin and engagement portion of the said activation shaft member beingmade convex and the other being made concave, whereby the said actuationshaft member sequentially effects two engagements in its rotationdirection with respect to the said contact pins so that the said contactportions are brought into contact with or separated from the saidelectrical component by one of the engagements portions and are slidwith respect to the said electrical component at the time of loading bythe other engagement.

Preferably, the engagement portion of the actuation shaft member has aconcave shape and the engagement portion is formed so as to push againstthe side surface of the electrical component at the time of loading ofthe electrical component.

Further preferably, an extension portion extended from a space betweenan external connecting terminal and a spring portion is formed on acontact pin, and the actuation shaft member is sandwiched by theengagement portions and the extension portions of the contact pins.

Further preferably, the electrical component is sandwiched by thecontact portions and the tip portions of the extension portions at theloading position, and at least one of the contact portions and the tipportions act as electrical conductive terminals with the electricalcomponent.

Further preferably, a spring portion is constituted by a first springportion provided on the contact portion side and a second spring portionprovided on the external connecting terminal side.

Further preferably, a plurality of ribs are disposed in parallel on theactuation shaft member, and the contact pins are isolated by the ribs,respectively.

Further preferably, a means for suppressing the rotation of theactuation shaft member by the spring member at a predetermined angularposition is provided in the base plate.

Further preferably, a cover member for rotating the actuation shaftmember against the force of the spring member via the arm is attached tothe base plate so that it can vertically move.

BRIEF DESCRIPTION OF THE DRAWINGS

Below, the present invention will be explained in detail referring tothe attached drawings. In the figures,

FIG. 1 shows a first embodiment of a socket assembly of the presentinvention, in which (a) is a vertical cross-sectional view of aprincipal part of the socket in a state before an IC chip substrate isinserted as an electrical component, (b) is a vertical cross-sectionalview of a principal part of the socket in a state where the slider ismoving, and (c) is a vertical cross-sectional view of a principal partof the socket in a completed insertion state;

FIG. 2 is a schematic plan view of a socket body of the firstembodiment;

FIGS. 3(a) and 3(b) are a side view and an end surface view of theslider of the first embodiment, respectively;

FIG. 4 is an explanatory view of an operation of an insertion jig usedin the socket assembly of the first embodiment;

FIG. 5 is an explanatory view of the operation of a detachment jig usedin the socket assembly of the first embodiment;

FIG. 6 is a view explaining an insertion method of a slider of the firstembodiment;

FIG. 7 is a vertical cross-sectional view of a part of the socketassembly showing a second embodiment of the present invention;

FIG. 8 is a vertical cross-sectional view of a part of the socketassembly showing a third embodiment of the present invention;

FIG. 9 is a perspective view of an IC chip mounted on the socketassembly;

FIG. 10 shows a part of the socket assembly according to a fourthembodiment of the present invention, in which (a) is a verticalcross-sectional view in a state where the IC chip is not mounted and (b)is a vertical cross-sectional view in a state where the IC chip ismounted;

FIG. 11 is a schematic plan view showing the arrangement of sliders ofthe fourth embodiment;

FIG. 12 is a schematic plan view of a socket body of a fourthembodiment;

FIG. 13 is a plan view showing a state where an IC chip is mounted on anIC socket according to a fifth embodiment of the present invention;

FIG. 14 is an enlarged view of a principal part of the socket shown inFIG. 13;

FIG. 15 is a partial perspective view seeing the slider used in the ICsocket of FIG. 13 from below;

FIG. 16 shows a slider used in the IC socket of FIG. 13, in which (a) isa partial front view of a slider, (b) is a partial bottom view of theslider, (c) is a side view of the slider, and (d) is a cross-sectionalview taken along a line 16(d)--16(d);

FIGS. 17(a) and 17(b) are cross-sectional views for explaining theoperation of the IC socket of the fifth embodiment, respectively;

FIG. 18 is a graph schematically showing the change of the spring forceof the arm when the slider of the IC socket of the fifth embodiment ismoved;

FIG. 19 is a partial cross-sectional view of the IC socket showing anexample of a modification of the slider of the fifth embodiment;

FIG. 20 is a partial cross-sectional view of the IC socket showing anexample of a modification of an attachment of the contact pins of thefifth embodiment;

FIG. 21 shows an IC socket according to a sixth embodiment of thepresent invention which enables the manufacture of an ultrahigh densityIC socket, in which (a) is a vertical cross-sectional view of aprincipal part of socket taken along a line 21(a)--21(a) of FIG. 22(a)in parallel to the first and second contact pins, (b) is similarly avertical cross-sectional view taken along a line 21(b)--21(b) in FIG.22(a) in contact with the surface of the first contact pin and fromwhich the second contact pin on a rear side is omitted, and (c) issimilarly a vertical cross-sectional view taken along a line21(c)--21(c) in FIG. 22(a) in contact with the surface of the secondcontact pin and from which the first contact pin on the rear side isomitted;

FIG. 22 is a rib arrangement view on a slider of the sixth embodiment,in which (a) is an explanatory view of a relationship with the first andsecond contact pins, (b) is a rib arrangement view of the upper surface,and (c) is a rib arrangement view of the lower surface;

FIG. 23 is a schematic plan view of the socket body of the sixthembodiment;

FIG. 24 is a side view of the slider of the sixth embodiment;

FIG. 25 is a vertical cross-sectional view of a part of the IC socketaccording to a seventh embodiment of the present invention;

FIG. 26 shows contact pins of a seventh embodiment, in which (a) is aside view of a third contact pin, and (b) is a side view of a fourthcontact pin;

FIG. 27 is a plan view of a part of a socket viewing the contact pins ofthe seventh embodiment from above;

FIG. 28 is a schematic perspective view of an overall configuration ofthe IC socket of the seventh embodiment;

FIG. 29 is a schematic plan view of the socket body of the IC socketshowing an eighth embodiment of the present invention;

FIGS. 30(a), 30(b), 30(c) and 30(d) are a plan view, a front view, aright side view and a bottom view schematically showing the slider ofthe eighth embodiment, respectively;

FIGS. 31(a), 31(b) and 31(c) are vertical cross-sectional views of aprincipal part for explaining a method of use of the IC socket of theeighth embodiment, respectively;

FIGS. 32(a), 32(b), 32(c) and 32(d) are schematic bottom views of aprincipal part for explaining the operation of the slider and thecontact pins in the IC socket of the eighth embodiment, respectively;

FIG. 33 is a cross-sectional view of a principal part showing aninsertion jig for moving the slider of the eighth embodiment from anopen position to a clamp position;

FIG. 34 is a cross-sectional view of a principal part showing a pull-outjig for moving the slider of the eighth embodiment from the clampposition to the open position;

FIG. 35 is a schematic structural view of a principal part of the ICsocket showing an example of a modification in which a change is addedto the orientation of the bent portions of the contact pins of theeighth embodiment;

FIG. 36 is a schematic structural view of a principal part of the ICsocket showing another example of a modification in which a change isadded to the orientation of the bent portions of the contact pins of theeighth embodiment;

FIG. 37 is a plan view of the principal part showing an example of amodification of a support construction of the contact pins of the eighthembodiment;

FIG. 38 is a vertical cross-sectional view of the principal part of theIC socket showing a ninth embodiment of the present invention resemblingthe eighth embodiment wherein the contact pins have support legs;

FIG. 39 is a vertical cross-sectional view of the principal part of theIC socket showing a 10th embodiment of the present invention resemblingthe eighth embodiment, wherein a spring means pressing against theslider is formed separately from the contact pin;

FIG. 40 is a vertical cross-sectional view of the principal part of theIC socket showing an 11th embodiment of the present invention resemblingthe eighth embodiment, providing a slider driving mechanism;

FIG. 41 shows a part of the IC socket according to a 12th embodiment ofthe present invention, in which (a) is a vertical cross-sectional viewin a state where the IC chip is not mounted and (b) is a verticalcross-sectional view in a state where the IC chip is mounted;

FIG. 42 is a schematic plan view of the IC socket showing thearrangement of the pivoting cam of the 12th embodiment;

FIG. 43 is a schematic plan view of the socket body of the 12thembodiment;

FIG. 44 is a cross-sectional view of the principal part showing a statewhere a chip-on-board module is mounted on the printed circuit boardusing the socket according to a 13th embodiment of the presentinvention;

FIG. 45 is a schematic plan view of the socket shown in FIG. 44;

FIG. 46 is a cross-sectional view of the principal part showing a statewhere the module is released from the socket shown in FIG. 44;

FIG. 47 is a schematic plan view of the socket shown in FIG. 46;

FIG. 48 is an enlarged cross-sectional view of the principal part of thesocket taken along a line 48--48 in FIG. 46;

FIG. 49 is a cross-sectional view of the principal part of the socketaccording to a 14th embodiment of the present invention;

FIG. 50 is a cross-sectional view of the principal part of the socketshowing a 15th embodiment of the present invention;

FIG. 51 shows an upper cap of the socket shown in FIG. 50, in which (a)is a plan view in a state where the lower surface of the upper cap isdirected upward, and (b) is a side view of the upper cap;

FIG. 52 is a cross-sectional view of the principal part of the socketshowing a 16th embodiment of the present invention;

FIG. 53 is a schematic plan view showing a relationship with the contactpins of the respective rows of the socket and the sliders according to a17th embodiment of the present invention;

FIG. 54 is a cross-sectional view of the principal part showing a statewhere the module is mounted on the circuit board by the socket accordingto the 18th embodiment of the present invention;

FIG. 55 is a cross-sectional view of the principal part showing a stagein which the contact pins of the socket are soldered onto the circuitboard according to the 18th embodiment;

FIG. 56 is a plan view showing the relationship between the contact pinsof the respective rows and sliders when the sliders of the 18thembodiment are located at the pressing position;

FIG. 57 is a plan view showing the relationship between the contact pinsof the respective rows and the sliders when the sliders of the 18thembodiment are located at the open position;

FIG. 58 is a plan view showing a metal plate for manufacturing thecontact pins of the respective rows of the 18th embodiment;

FIG. 59 is a plan view of the IC socket according to a 19th embodimentof the present invention showing a state where the IC package isattached;

FIG. 60 is a vertical cross-sectional view taken along a line 60--60 inFIG. 59 showing a state where a slider is located at the pressingposition;

FIG. 61 is a perspective view of the base plate and a slider cut along aline 61--61 in FIG. 59;

FIG. 62 is a perspective explanatory view of the principal parts showingthe relationship between the jig for attachment of the IC package andthe IC socket of the 19th embodiment;

FIG. 63 is a perspective view of the principal parts of the jig usedwhen taking the IC package out of the IC socket of the 19th embodiment;

FIG. 64 is a vertical cross-sectional view of a part of the socket takenalong a line 64--64 in FIG. 59 showing a state where the slider islocated at the open position and the IC package is inserted;

FIG. 65 is a vertical cross-sectional view taken along the line 65--65of FIG. 59 showing a state where a contact portion of a contact pin ispositioned above the IC package;

FIG. 66 is a vertical cross-sectional view taken along the line 66--66of FIG. 59 in a state where a contact portion of a contact pin abutsagainst the upper surface of the IC package;

FIG. 67 is a vertical cross-sectional view of a part of the socketshowing an example of a modification of the slider of the 19thembodiment;

FIG. 68 is a vertical cross-sectional view of a part of the socketshowing an example of a modification of the contact pin of the 19thembodiment;

FIG. 69 is a plan view of the IC socket according to the 20th embodimentof the present invention showing a state where the cover is removed atthe time of attachment of the IC package;

FIG. 70 is a cross-sectional side view of a part of the socket of the20th embodiment;

FIG. 71 is a vertical cross-sectional view of a part of the socket takenalong a line 71--71 in FIG. 70 in a state where the IC package isattached;

FIG. 72 is a schematic vertical cross-sectional view of a part of thesocket taken along a line 72--72 in FIG. 70;

FIG. 73 is a partial perspective view showing a base plate and anactuation shaft member cut along a line 73--73 in FIG. 70;

FIG. 74 is a vertical cross-sectional view similar to FIG. 71 in whichthe socket of the 20th embodiment is in an opening state;

FIG. 75 is a vertical cross-sectional view similar to FIG. 71 showing anexample of a modification of the contact pin and base plate of the 20thembodiment;

FIG. 76 is a vertical cross-sectional view showing an IC socketaccording to the 21st embodiment of the present invention; and

FIG. 77 is a vertical cross-sectional view of a part of the IC socket ofthe 21st embodiment in a state where the IC package is attached.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1 through FIG. 3, a socket assembly (IC socket)according to the first embodiment of the present invention is mounted ona printed circuit board 5 and is constituted so as to accommodate aleadless. IC chip 1 shown in FIG. 9. In this IC chip 1, an LSI(illustration is omitted) etc. is mounted on the upper surface of arectangular multiple layer substrate 2 formed by a glass epoxy resin orthe like, protected by the resin and formed into a module. A pluralityof terminals (pads or lands) 4 are arranged on the the bottom surface ofthe substrate 2 along the respective sides of the substrate 2.

The IC socket 10 is provided with a socket body 11 having a generallyrectangular configuration seen from above. Contact pins 12 respectivelyarranged in parallel and at predetermined intervals in directionsperpendicular to the respective sides are implanted in the respectivesides of this socket body 11. Also, guides 11b for positioning, locatedinside of the rows of the contact pins 12 with each same distance areprovided along a diagonal of a rectangle in the socket body 11. In thispositioning guide 11b, the upper surface has an L-shape, the bent insideof the L is directed to a central direction of the diagonal, and anupper half of the inside surface of the L is constituted by an inclinedplane inclined outward, an interval of vertical planes of the lower halfof the inside surfaces of the L's of the respective opposed positioningguides 11b is slightly larger than that of the substrate 2 of the ICchip 1 mounted on the socket body 11, and the movement of the substrate2 of the IC chip 1 to an extent where the wiping effect is obtained ispossible in a state where it is positioned only by the positioning guide11b.

Also, guide holes 11c are respectively provided at positionssubstantially intersecting the rows of the contact pins 12 on theoutside of the positioning guides 11b on the diagonals, and square holes11d are made at the positions respectively adjoining the row sides ofthe contact pins 12 with respect to these guide holes 11c.

The contact pin 12 having a base portion 12A and an arm 12B is ahorizontal U-shape and is formed with a contact portion 12b which facesupward at the tip portion of the lower side base portion 12A. Recesses12c are provided in succession at two portions on the deep side of the Uafter this contact portion 12b. Also, a circular portion 12a having adisk-like tip is projected outward at a position near the curved portionof the U, an external connecting portion 12d is projected outward at aroot position of the U, and a sliding portion 12f projected inward isformed in the vicinity of the tip of the arm 12B of the upper side ofthe U.

In the socket body 11, the circular portion 12a of the contact pin 12 isimplanted by press-fitting into a slit 11a made at a position where thecontact pin 12 should be implanted, and as a result, a slightinclination of the contact pin 12 is possible on the flat plane of thecontact pin 12 with respect to the socket body 11.

For this reason, due to a variation of shapes of contact pins 12a due toerror in manufacturing and a variation of the press-fit state when thecontact pins 12 are inserted into the slits 11a of the socket body 11,the positions in the height directions of the external connectingportions 12d of the contact pins 12 end up off. When the socket body 11is placed on the circuit board 5, even in a state where some of theexternal connecting portions 12d can not come into contact with theelectrode portions or conductive pattern of the circuit board 5, bypushing the IC socket against the circuit board, it is possible toincline the contact pins 12 and to bring all external connectingportions 12 into close contact with the conductive pattern of thecircuit board 5, and in addition, even if the pushing against the ICsocket is released, a tight contact state of the external connectingportions 12d and the conductive pattern of the circuit board 5 is kept,and therefore soldering work of the external connecting portions 12d ofthe contact pins 12 to the conductive pattern of the circuit board 5 canbe reliably carried out.

A straight slider 13 having a cross-section of a shape substantiallyresembling the character U is inserted into a space having a horizontalU-shape constituted by a row of the contact pins 12. At both ends ofthis slider 12, pins 14 which can be positioned at upper sides of thesquare holes 11d of the socket body 11 project longitudinally outwardbeyond the row of contact pins, ribs 13c and upper grooves 13d on anupper side and ribs 13c and lower grooves 13e on the lower side arealternately formed at the intermediate portion with the same pitch asthat of the row of the contact pins 12, respectively, and the front endside of the lower groove 13e forms a shape that can be engaged with therecess 12c. Also, a pressing portion 13b is formed at an upper end of apart facing the center of the socket body 11 so as to project therefrom,and an abutment portion 13a which abuts against the side surface of thesubstrate 2 of the IC chip 1 is formed substantially at the lower sideof the pressing portion 13b. Further, the bottom surface of the uppergroove 13d forms an inclined plane so that the pressing portion 13b sidebecomes lower when the slider 13 is inserted into the contact pin 12s.

With respect to the above-mentioned IC socket, in the insertion jig 16dfor inserting the IC chip 1, guide posts 16a which can be inserted intothe guide holes 11c at the four positions of the above-mentioned socketbody and leg portions 16c which can be inserted into the square holes11d are provided. The tips of the leg portions 16c form inward taperedportions 16b.

In a detachment jig 17, similar to the insertion jig 16, guide posts 17awhich can be inserted into the guide holes 11c at the four positions andleg portions 17c which can be inserted into the square holes 11d areprovided. The tips of the leg portions 17c form outward tapered portions17b.

Note that, in a method of inserting the above-mentioned slider 13 intothe contact pins 11 one by one (not a row, since a large force isnecessary for simultaneously opening all contact pins 12 and the pinscannot be opened easily), as shown in FIG. 6, rods 18 are made to abutagainst the recess 12c of the tip of the lower side of the contact pin12 and the recess 12c between the sliding portion 12f of the upper sideand the projection portion of the tip, respectively, the side:s are arevertically opened by these two rods 18, and the slider 13 is insertedtherein. Also, after the slider 13 is inserted into the row of thecontact pins 12, desirably the inclination angle of the bottom surfaceof the upper groove 13d is set so that the elastic deformation of thecontact pins 12 can be reduced as much as possible. If performing this,when the IC socket is not used, it is possible to prevent a load frombeing applied on the contact pins 12.

Next, the operation of the above-mentioned IC socket will be explained.First, when the IC chip 1 is inserted, at the part of the contact pin 12in the state before the insertion, as shown in FIG. 1(a), the slider 13is located in a state where the tip part of the lower portion of theslider 13 is inserted into the recess 12c at the deep side of theU-shaped space and merely the contact portion 12b of the contact pin 12is located at the position where the substrate 2 of the IC chip 1 is tobe placed. The slider 13 is completely retracted. When the substrate 2of the IC chip 1 is placed along the guides 11 for the positioning atthe four corners in this state, the substrate 2 of the IC chip 1 entersa state where the terminals 4 thereof are placed on the contact portions12b in contact with the same.

Next, the guide posts 16a of the insertion jig 16 are inserted into theguide holes 11c of the socket body 11 as shown in FIG. 4 and pusheddown, whereby the tapered portions 16b of the leg portions 16c pushagainst the pin 14 of the slider 13 inward and moves the slider 13 to astate of FIG. 1(c).

In the process of moves to this state, as shown in FIG. 1(b), thepressing portion 13b side of the slider 13 once rises so that the tipportion of the lower groove 13e goes over the adjoining portion of therecess 12c of the contact pin 12 and moves to the upper side of thesubstrate 2 of the IC chip 1.

In a state where the move is completed, as shown in FIG. 1(c), theabutment portion 13a of the slider 13 presses against the side surfaceof the substrate 2 of the IC chip 1, the substrate 2 of the IC chip 1 iscompletely positioned by the pressing by the abutment portions 13a ofthe four sliders 13 and, at the same time, the bottom portion of theupper groove 13d of the slider 13 is pressed downward by the elasticforce of the contact pins 12 via the sliding portions 12f of the contactpins 12 and the pressing portion 13b presses against the substrate 2 ofthe IC chip 1 from the upper side to bring the terminals 4 thereof intocomplete contact with the contact portion s12b of the contact pins 12.

In this case, the pressing point of the substrate 2 of the IC chip 1 bythe pressing portion 13b of the slider 13 shifts to a position furtherin than the contact portions 13b of the contact pins 12, and thereforeeven if a lop-sided pressing state of the substrate 2 of the IC chip 1occurs due to a time difference of the respective sliders 13 which mayoccur when pressing against the insertion jig 16, there will never be acase where an inclination of the substrate 2 of the IC chip 1 isproduced and the other sliders 13 abut against the side surfaces of thesubstrate 2 of the IC chip 1 to cause defective operation. Note that,the insertion jig 16 is removed from the socket body 11 after thecompletion of insertion of the substrate 2 of the IC chip 1.

Where detaching the substrate 2 of the IC chip 1, as shown in FIG. 5,the guide posts 17a of the detachment jig 17 are inserted into the guideholes 11c of the socket body 11 and pushed down, whereupon the taperedportions 17b of the leg portions 17c press the pins 14 of the sliders 13to the outside and move the sliders 13 to the state of FIG. 1(a). Inthis state, the substrate 2 of the IC chip 1 is merely sitting on thecontact portions 12b of the contact pins 12, and therefore the substrate2 of the IC chip 1 may be detached in this state. Then, after thesubstrate 2 of the IC chip 1 is detached, the jig is detached from thesocket body 11 similar to the case of the insertion jig 16.

FIG. 7 is a vertical cross-sectional view of a part of the IC socketaccording to the second embodiment of the present invention. In thisembodiment, no recesses 12c are provided in the contact pin 12, ahook-like portion 12e is provided in place of the circular portion 12a,and further an engagement portion 12i is provided on the socket body 11side of the external connecting portion 12d. Furthermore, a grooveportion 11e is provided in the end surface of the socket body 11, and aconvex portion 11f is provided at the bottom surface, respectively.

A contact pin 12 is attached to the socket body 11 by press-insertingthe hook-like portion 12e into the slit 11a made in the socket body 11and, at the same time, the engagement portion 12i is made to abutagainst the bottom surface of the socket body 11 while engaging theexternal connecting portion 12d with the groove portion 11e provided inthe end portion of the socket body 11.

At this time, the lower end of the contact portion 12b of the contactpin 12 abuts against the socket body 11. In the bottom surface of thesocket body 11, a gap is formed between the same and the circuit board 5to which the IC socket is attached by the convex portion 11f.

When adopting the configuration as mentioned above, even if a strongforce is applied to the external connecting portion 12b of a contact pin12, the lower end abuts against the socket body 11, and therefore thereis no risk of warping in the downward direction, and it is possible toprevent a situation wherein, when the substrate 2 of the IC chip 1 isplaced on the contact portions 12b of the contact pins 12 and thesliders 13 are moved, the external connecting portions 12b warp in thedownward direction, the pressing portions 13b of the sliders 13 catch onthe side surfaces of the substrate 2 of the IC chip 1, and it becomesimpossible to move the sliders 13 to the predetermined position.

Also, since no recesses 12c are provided in the contact pins 12, when aslider 13 is moved, it can be moved with a weaker force than that of thecase shown in FIG. 1. Further, the contact pins 12 are attached to thesocket body 11 by the external connecting portions 12d, the hook-likeportions 12e and the engagement portions 12i, and therefore no variationof position of the external connecting portions 12d in the height sdirection occurs, and the work of soldering the external connectingportions 12d to the circuit board 5 becomes easy.

FIG. 8 is a cross-sectional view showing a contact pin part of the ICsocket according to a third embodiment of the present invention. In thisembodiment, no slit 11a is made in the socket body 11, a leg portion 12gis extended to the bottom surface side of the socket body 11 from theexternal connecting portion 12d of the contact pin 12, and a pawlportion 12h is provided at the tip of the leg portion 12g. The pawlportion 12h is engaged with the step portion 11g provided at the bottomsurface of the socket body 11 while engaging the external connectingportion 12d with the groove portion 11e of the socket body 11 similar toa case shown in FIG. 7, whereby the contact pin is attached to thesocket body 11.

Note that, also in this case, a convex portion 11f is provided at thebottom surface of the socket body 11, the lower end of the contactportion 12b of the contact pin 12 abuts against the socket body 11, andno recesses 12c are provided.

In the first through third embodiments mentioned above, themanufacturing of a thin socket is possible. For example, even in a casewhere the width of the substrate 2 of the IC chip 1 is 25 mm and thethickness is 0.4 to 0.5 mm, sockets having a width of 32 mm and athickness of not more than 3 mm can also be manufactured.

Also, the pressing force between a terminal 4 of the substrate 2 of theIC chip 1 and a contact portion 12b of a contact pin 12 is caused onlyby the resiliency of the contact pin 12 in a state sandwiching in theslider 13 and the substrate 2 of the IC chip 1. No load is applied onthe socket body 11 made of the plastic, therefore this socket has a highreliability at the time of high temperature and can be utilized also ina burn-in test, and a reflow for soldering to the substrate 2 of the ICchip 1 after that test can be passed, and thus a waste-free productionprocess can be realized.

Further, even if the number of the contact pins 12 is large, anelectrical component such as a substrate 2 of an IC chip etc. can beattached by an automatic machine.

Further, when the abutment portion 13a of the slider 13 comes intocontact with the side: surface of the substrate 2 of the IC chip 1, thesubstrate 2 of the IC chip 1 is slightly moved with respect to thecontact portions 12b of the contact pins 12, and therefore a wipingeffect is reliably obtained and poor contact does not occur.

Further, in this system, the substrate 2 of the IC chip 1 is placed onthe contact portions 12b of the fixed contact pins 12, and the substrate2 of the IC chip 1 etc. are pressed from above by the sliding portions12f of the contact pins 12 via the sliders 13, and therefore an intendedcontact pressure is easily obtained also by fine pitch contact pins 12.

Note that, in the above-mentioned embodiments, only an example in whichthe substrate 2 of the IC chip 1 is attached is shown, but by changingthe size of respective elements of the socket, it is also possible tohandle an IC package or a chip-on-board module.

Further, when adopting a configuration wherein the lead terminal issandwiched instead of sandwiching the substrate 2 of the IC chip 1 bythe pressing portion 13b of a slider 13 and the contact portions 12b ofthe contact pins 12, it is also possible to handle an IC package inwhich the lead terminals are projected to the side.

Next, referring to FIG. 10 through FIG. 12, an IC socket 110 accordingto a fourth embodiment of the present invention comprises a socket body111 having a generally rectangular configuration, a plurality of contactpins 121 having a horizontal U-shape which are arranged in parallel tothe respective sides of this socket body 111 so as to form rows andsliders 122 inserted into the internal spaces of the horizontal U-shapedspaces formed by the rows of these contact pins 121.

In the socket body 111, positioning guides 111a positioned inside of therows of the contact pins 121 at identical distances are provided alongthe diagonals thereof.

A contact pin 121 is constituted by a base portion 121a which is thelower side of the U, an inclined plane 121i inward with respect to theupper surface of the center of the socket of this base portion 121a, acontact portion 121b which is provided upward on the tip of the furtherinside thereof, a step portion 121c provided on the upper side of thebase portion 121a in the vicinity of this contact portion 121b, a legportion 121d which is projected to the lower side of the base portion121b and implanted in the socket body 111, an external connectingportion 121e which is projected at the outside end portion of the baseportion 121a so as to be connected to the external circuit, a curvedportion 121f which has an arm extended curved upward from the attachmentportion of this external connecting portion 121e, in which the arm beingcurved inward to the upper portion from the attachment portion of theexternal connecting portion 121e, a horizontal portion 121g extendedinward from the tip of this curved portion 121f, and a securing portion121h provided downward at the tip of this horizontal portion 121g.

The slider in the fourth embodiment comprises a movable member 122, astationary member 123 and a driving member 124.

The stationary member 123 is arranged so that the bottom surface is incontact with the upper sides of the leg portions 121d of the contactpins 121, the center side of the socket abuts against the step portions121c, and the outside abuts against the inside of the curved portions121f to be affixed.

Further, a rack 123a is formed on the upper surface of the stationarymember 123, and an inward inclined plane 123b is formed on the uppersurface on the center of the socket.

The upper surface of the movable member 122 is in contact with the lowersurfaces of the horizontal portions 121g of the contact pins 121, thetip portion on the center of the socket reduces the elastic force fromthe elastic portions 121h of the contact pins 121 to the movable member122, and an inward first inclined plane 122d reducing the bending of thecontact pins 121 and further this tip form a downward pressing portion122a.

On the other hand, a rack 122c is formed on the lower surface of themovable member 122, an outward second inclined plane 122d is formed onthe center side of the socket of this rack 122c, and further this tipside becomes the guide portion 122e and the vertical abutment portion122b connected to this.

The driving member 124 has a pinion 125 engaged with the racks 122c and123a of the above-mentioned movable member 122 and the stationary member123, drive levers 126 respectively projecting in the same direction areprovided on the opposite end portions of this pinion 125, and themovable member 122, the stationary member 123 and the driving member 124operate in association

An explanation will be made next of the operation of the slider.

First, when the drive lever 126 is raised from a substantiallyhorizontal position shown in FIG. 10(b) to substantially a verticalposition shown in FIG. 10(a), the pinion 125 rotates in acounterclockwise direction in the figure. At this time, the pinion 125is engaged with the rack 123a of the stationary member 123, andtherefore pivots to the outside (left side in the figure). Along withthis pivoting, the rack 122c of the movable member 122 engaged with thepinion 125 shifts to the outside (left side in the figure) with only adistance two times the pivoting distance of the pinion 125. Along withthis movement, the guide portion 122e of the movable member 122 abutsagainst the inclined planes 121i of the contact pins 121, the movablemember 122 is then pushed upward, the press contact against the ICpackage by the pressing portion 122a of the movable member 122 isreleased, and a state enabling insertion of the IC package isestablished.

When the IC package is inserted from the upper side along thepositioning guide 111a in this state, and the drive lever 126 is throwndown toward the inside of the socket, the pinion 125 rotates in theclockwise direction in FIG. 10(a) to pivot toward the inside of thesocket on the rack 123a of the stationary member 123 and, at the sametime, move the rack 122c of the movable member 122 exactly a distance oftwo times toward the inside of the socket.

Along with the movement of the movable member 122, the guide portion122e of the movable member 122 abuts against the inclined planes 121i ofthe contact pins 121, and thereafter the movable member 122 is guided bythe inclined planes 121i of the contact pins 121 and gradually shiftsforward and downward. As a result, the abutment portion 122b of themovable member 122 pushes against the side surface of the substrate 2 ofthe inserted IC package to correctly position the substrate 2 and, atthe same time, a state where the arm sliding portions 121g of thecontact pins 121 in contact with the first inclined plane 122d arepushed upward is established. Therefore, as a reaction thereof, thepressing portion 122a at the tip of the movable member 122 pressesagainst the upper surface of the substrate 2 of the IC package by theelastic force of the arms of the contact pins 121, and acts so that theelectrodes of the bottom surface of that substrate 2 come into completecontact with the contact portions 121b of the contact pins 121.

Where the IC package is to be removed, it is sufficient if an operationreverse to that mentioned above is carried out, so an explanation willbe omitted.

Also, even in a case where an engagement portion of the stationarymember, movable member and the driving member is a friction surface ofnot illustrated serrations, the operation is exactly the same, andtherefore an explanation will be omitted.

As mentioned above, in the IC socket of the fourth embodiment, the stateof the contact pins can be changed just by operating the drive lever,and therefore special equipment such as an insertion jig, removal jig,etc. are unnecessary.

Further, it is possible to move the slider by exactly the same distanceover the entire length, and in addition the sliding member is themovable member of the slider, and therefore it very lightly actuates.Also, the operation of the slider is just to raise or lower the drivelever, and therefore even in a case where a pressing force from the topis not imparted to the socket and it is mounted on a large size printedcircuit board or a thin printed circuit board, there is no danger ofwarping or damage of the printed circuit board.

Next, referring to FIG. 13 through FIG. 18, the IC socket 210 accordingto a fifth embodiment of the present invention is provided with a socketbody 211 having a generally rectangular configuration made of a plastic.At the center of this socket body 211, an opening 211a having agenerally rectangular configuration smaller than the outer dimensions ofthe substrate 2 of the IC chip 1 is provided. As shown in FIG. 13 andFIG. 14, corner engagement pieces 211b for positioning the IC chip 1 onthe socket body by engaging with each of the four corner portions of theIC chip 1 are formed at the upper surface of the socket body 211 so asto project therefrom. Note that, so as to enable the wiping actionmentioned later, the corner engagement pieces 211b position the IC chip1 to an extent enabling a slight free movement of the IC chip. Also,positioning holes 211c for positioning the socket body 211 on theprinted circuit board 5 (refer to FIG. 17 ), temporarily holding, oraffixing the same are formed at the four corner portions of the socketbody 211.

A plurality of contact pins 220 made of metal are arranged and affixedon the side portions of the socket body 211 corresponding to thearrangement of the electrodes or terminals 4 along the sides of thesubstrate 2 of the IC chip 1. As shown in FIG. 17(a), each contact pin220 has a base portion having a contact portion 220a formed thereon,which comes into contact with an electrode 4 of the bottom surface ofthe IC chip 1, on one end. An external connecting portion 220b projectedto the external portion of the socket body 211 is formed at the otherend of the base portion. The external connecting portion 220b of thecontact pin 220 can be soldered onto the conductive pattern(illustration is omitted) formed on the printed circuit board 5 on theoutside of the socket body 211. A downward projection portion 220c isformed on the base portion of each contact pin 220. By press-fittingthis projection portion 220c into a slit 211d formed in the uppersurface of the socket body 211, the contact pin 220 is implanted in theupper surface of the socket body 211. Also, on one end portion of eachcontact pin 220, an engagement portion 220d for engaging with a guidegroove 211 formed in the upper surface of the socket body 211 isprojected downward. By an engagement of this engagement portion 220dwith the guide groove 211e, one end portion 220a of the contact pin 220is positioned on the socket body 211.

As shown in FIG. 13, the IC socket 210 is further provided with aplurality of (here, four) sliders 230 which individually press againstthe respective sides of the substrate 2 of the IC chip 1 to bring theelectrodes 4 of the IC chip 1 into press-contact with the contact pins220 at each side. The sliders 230 are made of a plastic. Referring toFIG. 15 through FIG. 17, each slider 230 has one end portion 230apressing against the substrate 2 of the IC chip 1 and another endportion 230b on an opposite side thereof. A notch 230c for abuttingagainst the side surface and upper surface of the substrate 2 of the ICchip 1 is formed in the one end portion 230a of each slider 230. Also, aplurality of arm insertion holes 230d opened on the other end portion230b side are formed in each slider 230.

On the other hand, an arm 221 for insertion into an arm insertion hole230d of the slider 230 is integrally formed on each contact pin 220. Thearms 221 hold the slider 230 and, at the same time, impart a springforce to the slider 230 and guide the slider 230 so that it can movefrom an open position or retracted position away from the IC chip 1(FIG. 17(a)) to a pressing position for pressing against the uppersurface of the substrate 2 of the IC chip 1 (FIG. 17(b) ) along theupper surface of the contact pins 220. The contact pins 220 can beeasily formed by punching of a metal plate.

As shown in FIGS. 17(a) and 17(b), in the upper surface in the vicinityof the contact portion 220a of each contact pin 220, a recess 220e whichmoves the slider 230 reaching near the IC chip 1 downward under thespring force of the arm 221 is formed. Each arm 221 is extended inclineddownward from above in the vicinity of the other end of the contact pin220 toward the contact portion 220a of the contact pin 220 so that thespring force given to the slider 230 is increased as the slider 230approaches the recess 220e of the upper surface of the contact pin 220.The base portion side of the arm 221 is formed to be bent so as to forman arc so as to impart a spring property to the arm 221.

Further, as shown in FIG. 17(a), the slider 230 has an upper thickportion 230e covering the upper surface of the arm 221 and a lower thickportion 230f covering the lower surface of the arm 221, and the upperthick portion 230e of the slider 230 is extended to the other endportion 230b side of the slider 230 longer than the lower thick portion230f. The arm insertion holes 230d of the slider 230 are opened at theend surface of the lower thick portion 230f. Also, arm guide grooves230g continuous to the arm insertion holes 230d are formed in the lowersurface of the upper thick portion 230e of the slider 230. Further, inthis embodiment, as seen from FIGS. 16(a) and 16(d), each five arminsertion holes 230d are mutually communicated on the lower side of theupper thick portion 230f. By such a shape, it becomes possible; toensure the strength of the slider 230 and it becomes possible to ensurethe strength of the mandrel (not illustrated) for forming the arminsertion holes 230d at the shaping of the slider 230.

Further, a slide contact portion 230h which is in sliding contact withthe upper surfaces of the contact pins 220 is formed at the lowersurface of one end portion 230a of the slider 230 so as to projecttherefrom. The slider 230 is formed so that only the slide contactportion 230h comes into sliding contact with the upper surfaces of thecontact pins 220. Also, as shown in FIG. 15 and FIGS. 17(a) and 17(b),guide ribs 230i which are engaged so that they can slide betweenmutually adjoining contact pins 220 are formed on the lower surface ofthe slider 230 so as to project therefrom.

In the IC socket 210 having the above-described configuration, when aplurality of sliders 230 held by the arms 221 integral with the contactpins 220 are individually slid after placing the substrate 2 of the ICchip 1 on the contact portions 220a of the contact pins 220, when thesliders 230 move downward along the recess 220e of the upper surfaces ofthe contact pins 220 by the spring force of the arms 221, theyindividually push the sides of the substrate 2 of the IC chip 1 andbring the electrodes 4 of the IC chip 1 into press-contact with thecontact portions 220a of the contact pins 220 for each side by theirpressing force. In this case, it is necessary to ensure a desiredcontact pressure between the electrodes 4 of the IC chip 1 and thecontact pins 220, but the electrodes 4 of the IC chip 1 can beindividually brought into press-contact with the contact pins 220 ateach of the sides by the sliders 230, and therefore the pressing forceby the sliders 230 can be reduced. Accordingly, the sliding operation ofthe sliders 230 can be easily carried out with a light force. Moreover,also the pressing force applied to the IC chip 1 becomes small, andtherefore it is possible to prevent an unnecessary stress from beingapplied to the IC chip 1 or the socket body 211. Particularly, since theportion pressing the IC chip by the sliders 230 and the portionsupporting the IC chip by the contact pins 220 are located at positionsalmost opposite to each other and only a compression stress in thethickness direction is substantially produced in the IC chip 1, it ispossible to prevent unnecessary stress from being applied upon internalcircuits of the IC chip 1.

Also, it is possible to individually slide the sliders 230 tosequentially press against the sides of the substrate 2 of the IC chip1, and therefore it is possible to move the IC chip 1 in the slidingdirection of a slider 230 within a range of the clearance between the ICchip 1 and the socket body 211 in a state where the IC chip 1 is pressedby the slider 230. Accordingly, a wiping action can be produced betweenthe electrodes 4 of the IC chip 1 and the contact portions 220a of thecontact pins 220, and the reliability of the electrical connection canbe improved.

Further, the sliders 230 are held at the arms 221 so as to cover theupper surfaces of the arms 220 on each side portion of the socket body211, and therefore the sliders 230 are useful as covers protecting theupper portions of the contact pins 220 and arms 221. Also, it ispossible to easily slide the sliders 230 by directly operating thesliders 230 from above the arms 221, and therefore a jig for sliding thesliders 230 etc. can be omitted, so the construction of the IC socket210 can be simplified and, at the same time, the reduction of size andweight and particularly the reduction of thickness thereof becomespossible.

Here, explaining the operation of the arms 221 and the sliders 230 infurther detail, when a slider 230 held at the arms 221 is located at theretracted position, as shown in FIG. 17(a), the slider 230 is inpress-contact with the upper surfaces of the contact pins 220 at theposition of the contact portions 230h by receiving the spring force ofthe arms 221. At this time, the spring force of the arms 221 acts on theslider 230 with the upper thick portion in the vicinity of the baseportion of the arm 221 as a support point and with the lower surface ofthe tip portion of the arm 221 as the power point.

Next, when the slider 230 is pushed from the retracted position to thedirection of the IC chip 1, the slider 230 moves along the uppersurfaces of the contact pins 220 while elastically deforming thedownward inclined arms 221 upward. Accordingly, as the contact portion230h of the slider 230 approaches the recesses 220e of the uppersurfaces of the contact pins 220, the spring force of the arms 221 isincreased. FIG. 18 shows the situation of change of the spring force ofthe arms 221 according to the movement of the slider 230. As shown inthe same figure, when the slider 230 reaches the recesses 220e of theupper surfaces of the contact pins 220 and starts to move downward, thespring force of the arms 221 starts to fall from the peak value. Asshown in FIG. 17(b), however, by a slight downward movement of theslider 230, the notch 230c of one end portion 230a of the slider 230abuts against the upper surface of the substrate 2 of the IC chip 1, andtherefore the spring force of the arms 221 becomes constant at a valueslightly lower from the peak value.

In this way, the spring force of the arms 221 is increased as the sliderapproaches the recesses of the upper surfaces of the contact pins, andtherefore when the slider 230 is slid against the spring force of thearms 221, that slider 230 can reach the upper surface of the substrate 2of the IC chip 1.

Further, in an IC socket 210 having the above-described configuration,when a slider 230 is slid to press against one side of the substrate 2of the IC chip 1, the side surface and upper surface of the substrate 2of the IC chip 1 can be pressed by the notch 230c of the slider 230.Therefore, by sequentially pressing against the opposed two sides of thesubstrate 2 of the IC chip 1 by two sliders 230, a further effectivewiping action can be produced between the electrodes 4 of the IC chip 1and the contact portions the contact pins 220.

Also, since the upper thick portion 230e of the slider 230 covering theupper surfaces of the arms 221 is extended longer than the lower thickportion 230f of the slider 21, the upper portions of the arms 221 can bewidely protected. Also, each arm insertion hole 230d of the slider 230is formed short so as to open at the end surface of the lower thickportion 230f shorter than the upper thick portion 230e of the slider230, and therefore the shaping of the slider 230, particularly theshaping of the arm insertion hole 230d becomes easy. Further, an armguide groove 230g continuous to each arm insertion hole 230d is formedin the lower surface of the upper thick portion 230e of the slider 230,and therefore even if the slider 230 is slid, the slider 230 can bestably held on the arm 221 and, at the same time, mutually adjoiningarms 221 can be stably held in a separated state by the arm guide groove230g.

Also, when the slider 230 is slid, only the slide contact portion 230hof lower surface of one end portion 230a of the slider 230 can bebrought into sliding contact with the upper surfaces of the contact pins220, and therefore it is possible to reduce the sliding resistance ofthe slider 230 to facilitate the sliding operation thereof.

Further, it is possible to slide the slider 230 to the pressing positionwhile maintaining mutually adjoining contact pins 220 at a constantinterval by the guide ribs 230i of the slider 230, and therefore poorcontact between electrodes 4 of the IC chip 1 and contact pins 220 dueto the position deviation of the contact pins 220 can be reliablyprevented, and the reliability of electrical contact between theelectrodes 4 and the contact pins 220 can be further improved.

FIG. 19 shows an example of a modification of the slider 230. In thesame figure, constituent elements similar to those of theabove-described fifth embodiment are given the same references. In thisembodiment, the upper thick portion 230e of the slider 230 is extendedlonger than the slider 230 of the above-described embodiment. Also, aprojection portion 230j provided with unevenness at the surface isformed on the upper surface of the other end portion 230b of the slider230. Accordingly, by making the finger tip or the like abut against thisprojection portion 230j when sliding the slider 230, the slider 230 canbe further easily pushed.

FIG. 20 shows an example of a modification of the attachment structureof the contact pins 220. In the figure, constituent elements similar tothose of the fifth embodiment are given the same references. In thismodified example, the guide ribs 211f sandwiching the externalconnection portion 220b of each contact pin 220 are formed on the outersurface of the socket body 211 so as to project therefrom. Accordingly,the external connection portions 220b of the contact pins 220 can beheld at the predetermined pitch.

FIG. 21 through FIG. 24 show an IC socket 310 according to a sixthembodiment of the present invention by which an ultrahigh densityarrangement of the contact pins is possible.

Referring to these figures, the IC socket 310 of the sixth embodiment isprovided with a socket body 311 having a generally rectangularconfiguration. First contact pins 312 and second contact pins 313 arealternately arranged in parallel to each other so as to form rows onrespective sides of the socket body 311. The socket body 311 is providedwith positioning guides 311b positioned inside the rows of the first andsecond contact pins 312 and 313. The first and second contact pins 312and 313 have lower side base portions 312a and 313a having a horizontalU-shape and upper continuous curved portions 313e and 313e constitutingthe arm and horizontal portions 312f and 313f. Upward contact portions312b and 313b are provided on one end of the base portions 312a and 313aof the first and second contact pins 312 and 313, and externalconnection portions 312d and 313d projected downward to the outside ofthe socket body 311 are provided on the other end of the base portions312a and 313a. Also, leg portions 312c and 313c projected downward areprovided at substantially the centers of the base portions 312a and313a. A slider 314 is arranged so that it can slide in a lateraldirection in an inner space of the U-shape formed by an arrangement ofthe first and second contact pins 312 and 313.

In the contact pin arrangement section of the socket body 311, provisionis made of first slits 311c and second slits 311d arranged in two rowsso as to fit the leg portions 312c and 313c of the first and secondcontact pins 312 and 313, respectively, and first socket body ribs 311fand second socket body ribs 311g alternately arranged so that the firstand second contact pins 312 and 313, inserted in the recesses 311eprovided for insertion of the contact portions 312b and 313b, areinserted in the recesses 311e at the outside and inside positions of thesocket body 311. The first and second slits 311c and 311d and the firstand second socket body ribs 311f and 311g are arranged with same pitch,respectively, as the first and second pitches deviated from each otherby a half pitch, so are overall arranged in a zigzag manner.

The leg portions 312c of the first contact pins 312 are inserted intothe first slits 311c, the lower sides of the contact portions 312b areinserted between the first socket body ribs 311f of the recess 311e ofthe socket body 311, the tips of the curved portions 312e constituteoblique upward first inclined portions 312h, the tips thereof becomeshorizontal portions 312f, and the further tips thereof become obliquedownward second inclined portions 312i. The tips of these constitute thedownward elastic portions 312g which resiliently press against the uppersurface of the slider 314.

The leg portions 313c of the second contact pins 313 are inserted intothe second slits 311d, the lower sides of the contact portions 313b areextended long and inserted between the second socket body ribs 311g ofthe recess 311e, the tips of the curved portions 312e immediately becomehorizontal portions 312f, and the tips of the horizontal portions 313fconstitute the downward elastic portions 313g.

Ribs holding the intervals of the first and second contact pins 312 and313 arranged at a constant interval are alternately arranged at the sameintervals as that for the first and second slits 311c and 311d in theslider 314.

On the upper surface inside the socket, first ribs 314a arranged at thesame pitch as that for the first or second contact pins 312 or 313,third ribs 314c arranged at the same pitch on the upper surface of aninternal portion, second ribs 314b arranged at the same pitch on theupper surface on the outside of the socket, and fourth ribs 314darranged on the lower surface of the outside of the socket are providedat the same pitch.

Also, the tip portion of the inside of the socket is constituted by adownward pressing portion 314e pressing against the IC chip, an abutmentportion 314f defining the side surface position of the placed IC packageand a pin 315 passed through in a longitudinal direction slightlyoutside from the center position.

The above-mentioned first and second ribs 314a and 314b are arranged atthe same pitch as that for the second contact pins 313 and, at theposition on the same vertical plane, and the third and fourth ribs 314cand 314d are arranged at the same pitch as that for the first contactpins 312 and on the same vertical plane.

In this case, the third ribs 314c are constituted so that the horizontalportions 312f of the first contact pins 312 pass above them, and thefourth ribs 314d are constituted so that they do not reach the part ofthe curved portions 312e, and therefore the first contact pins 312 arearranged at a position where they are not in contact with the third andfourth ribs 314c and 314d.

Also, the curved portions 313e and the horizontal portions 313f of thesecond contact pins 313 are directly connected, and therefore the secondribs 314b are constituted so as to be located on lower sides of thisexternal connection parts. With respect to the first ribs 314a, theelastic portions 313g are constituted so as to be located at a rearposition than the elastic portions 312g of the first contact pins 312,and therefore they do not come into contact with each other.

Where the IC chip is mounted on the above-mentioned IC socket, first, byboth end portions of the contact pins 315, the slider 314 is slid to theoutside direction of the socket by an exclusive detachment jig to exposethe contact portions 312b and 313b, and the IC chip is placed on this.

In this case, where the positioning guides 311b separately exist, the ICchip is placed along them, whereby it is possible to bring therespective contact portions 312b and 313b and the terminals of the ICchip into coincidence with each other in their positions in advance.

When the sliders 314 are slid to the center direction of the socket bythe exclusive insertion jig after mounting the IC chip, the pressingportions 314e are slid to the positions above the contact portions 312band 313b, the IC chip is pressed against the contact portions 312b and313b from the upper side by the elastic portions 312g and 313g of thecontact pins 312 and 313 and, at the same time, the abutment portions314f abut against the side surface of the IC chip, so the positioning iscorrectly executed.

Note that, where the IC chip is to be removed, it is sufficient if anoperation reverse to that mentioned above is carried out.

FIG. 25 through FIG. 28 show the IC socket 310 according to a seventhembodiment of the present invention with which an ultrahigh densityarrangement of the contact pins resembling the sixth embodiment ispossible. In these figures, constituent elements similar to those of thesixth embodiment are given the same references.

Referring to these figures, the third contact pin 315 of the seventhembodiment is a contact pin having a short dimension, the leg portion315c thereof is projected downward from the substantial center of thebase portion 315a, the tip portion inside the socket is constituted by apart inserted into the recess 311e of the socket body 311, an upwardcontact portion 315b is formed at the center portion inside the recess311e at a further tip portion thereof, and an insertion portion 315jformed with a right angle so as to be inserted between the socket bodyribs 311f is formed on the leg portion 315c side of the insertion part.

An external connecting portion 315d for connection to the externalcircuit outside of the socket is formed at an end portion on the outsideof the third contact pin 315.

The fourth contact pin 316 is a contact pin having a long dimension, theleg portion 316c thereof is projected downward on the externalconnecting portion 316d side on the outside from the center of the baseportion 316a, the tip portion inside the socket is constituted by a partfully inserted into the recess 311e of the socket body 311, and at afurther tip portion thereof, an upward contact portion 316b is formed.An insertion portion 316j formed with a right angle so as to be insertedbetween the socket body ribs 311g is formed on the lower side of thiscontact portion 316b.

Also, the leg portion side of the insertion part is formed so as to forman inclined plane portion 316h and pass above the socket body ribs 311f.

In the above-mentioned socket body ribs 311f and 311g, as shown in FIG.25 and FIG. 27, both of the 311g on the inside of the socket of therecesses 311e and 311f on the outside thereof are formed in a triangleshape over a part of the side surface and lower surface, the 311g arepositioned on an extension of the third contact pin 315, and the 311fare positioned on the lower side of the inclined plane portion 316k ofthe fourth contact pin 316.

As one schematic example of an overall configuration of this socket,there is the one shown in FIG. 28. In this example, the IC chip isplaced on the contact pins 315 and 316 arranged in the socket body 311,a pressing cap 317 is pushed from the upper side, and the pressing cap317 is engaged with the socket body 311 to press the downward electrodesof the IC chip against the contact portions of the contact pins 315 and316.

As mentioned above, in the sixth and seventh embodiments of the presentinvention, in the contact pin arrangement portion, at least one set oftwo ribs for maintaining the intervals of the contact pins and arrangedat constant intervals on the left and right of a contact pin aredisposed for each contact pin, one rib for mutually adjoining contactpins is placed at a substantially intermediate position of thearrangement of the set of the other ribs and one of the mutuallyadjoining contact pins is on the arrangement of the other ribs for thecontact pins, and therefore it is possible to suppress an influence ofthickness of the ribs, which limited making the arrangement intervals ofthe contact pins as narrower as possible, and so contact pins can bearranged with a very high density.

Also, by this, an ultrahigh density IC chip which has beenconventionally impossible can be mounted on a printed board or the likein a manner enabling replacement.

FIG. 29 to FIG. 34 show an eighth embodiment of the present invention.

Referring to FIG. 29 through FIG. 32 at first, the IC socket indicatedoverall by the reference numeral 410 is provided with a socket body 411having a generally rectangular configuration frame-like shape; made of aplastic. Corner engagement pieces 411a for engagement with for examplethe respective four corner portions of the substrate 2 of the IC chip 1shown in FIG. 9 and for positioning the substrate 2 of the IC chip 1 onthe socket body 411 are formed on the upper surface of the socket body411 so as to project therefrom. Note that, so as to enable the wipingaction in the front and rear direction mentioned later, the respectivecorner engagement pieces 411a position the IC chip 1 to an extent thatallows a slightly free movement of the substrate 2 of the IC chip 1.Also, at the four corner portions of the socket body 411, positioningholes 411b for positioning the socket body 411 on the printed circuitboard (not illustrated), temporarily stopping or fixing the same areformed at the four corner portions of the socket body 411. Thepositioning holes 411b can be used for guiding the jig for moving theslider mentioned later.

A large number of contact pins 420 are arranged on the upper surface ofthe respective side portions of the socket body 411 at constantintervals in directions orthogonal to the plate thickness directionthereof. Each contact pin 420 has a base portion 421 extended in aninward and outward direction of the side portion of the socket body 411and an arm 422 constituting a spring means mentioned later, an upwardcontact portion 421a which is in contact with a terminal 4 of the ICchip 1 in the vicinity of the inner edge of the side portion of thesocket body 411 and supports the bottom surface of the IC chip 1 isformed on one end of the base portion 421, and a surface mounting typelead terminal or external connecting portion 421b extended to theoutside of the frame piece portion of the socket body 411 is formed atthe other end of the base portion 421. This external connecting portion421b is connected onto the circuit pattern of a printed circuit board(not illustrated) by for example soldering, etc. Between the contactportion 421a of the base portion 421 of the contact pin 420 and theexternal connecting portion 421b, a fitting portion 421c projecteddownward is formed in the vicinity of the external connecting portion421b, and a fitting groove 411c accommodating the fitting portion 421cis formed in the upper surface of the socket body 411. Also, ribs 411dand 411e sandwiching in the base portion 421 of the contact pin 420 bythe inside (front side) and the outside (rear side), respectively areprovided on the upper surface of the socket body 411 so as to projecttherefrom. As seen from FIG. 31(a), the contact portion 421a of thecontact pin 420 acts as a free end of the base portion 421 of thecontact pin 420, and therefore the contact portion 421a of the contactpin 420 can warp and resiliently displaces in a thickness direction,that is, in an arrangement direction of the contact pins 420 with thefitting portion 421c or the rib 411d on the front side (inner side)thereof as the support point.

A slider 430 extended along the arrangement direction of the contactpins 420 is provided on the respective side portions of the IC socket410 so that it can move along the length direction of the base portions421 of the contact pins 420. As shown in FIG. 31(a), a side surfaceabutment portion 430a which can abut against the side surface of thesubstrate 2 of the IC chip 1 and a pressing portion 430b which can abutagainst the upper surface of the substrate 2 are formed on one end ofthe slider 430. A shaft 431 passing through the slider 430 in the lengthdirection is integrally provided at the other end portion of the slider430 by for example insert shaping, etc., and both ends of this shaft 431are projected outward from the opposite end portions of the slider 430,respectively. The slider 430 is held between the base portions 431 ofthe contact pins 420 and the arms 422. By this, the slider 430 can movebetween an open position at which the pressing portion 430b opens themounting region of the IC chip 1 (refer to FIG. 31(a)) and a clampposition at which the pressing portion 430b comes into press-contactwith the upper surface of the substrate 2 of the IC chip 1, and one endsurface 430a abuts against the side surface of the substrate 2 (refer toFIG. 31(c)) along the upper surface of the base portion 421. Thevicinities of the contact portions 421a of the base portions 421 arebent downward to exhibit a convex shape, whereby recesses 421d areformed in the upper surfaces in the vicinity of the contact portions421a of the base portions 421. Then, corresponding to the recesses 421d,recesses 430c are formed in the lower surface of the slider 430.Accordingly, when the pressing portion 430b of the slider 430 approachesthe upper surface of the substrate 2 of the IC chip 1 from the openposition, one end of the lower surface of the slider 430 moves downwardalong the recesses 421d, and therefore also the pressing portion 430b ofthe slider 430 moves downward while advancing accompanied with this, andabuts against the upper surface of the substrate 2 of the IC chip 1(refer to FIG. 31(b)). Then, thereafter the slider 430 can furtheradvance while making the pressing portion 430b abut against the uppersurface of the substrate 2, and the side surface abutment portion 430aof the slider 430 abuts against the side surface of the substrate 2 inthe end (refer to FIG. 31(c)), but when there is a clearance between thesubstrate 2 of the IC chip 1 and the corner portion 411a of the socketbody 411, it is possible to make the slider 430 further advance exactlyby an amount of that clearance and push the side surface of thesubstrate 2 of the IC chip 1 by the side surface abutment portion 430a.

The contact pin 420 is made of a metal which is rich in a springproperty, and the slider 430 is formed so as to gradually open the arms422 upward with respect to the base portions 421 when the slider 430moves from the open position to the clamp position. Therefore as theslider 430 approaches the substrate 2 of the IC chip 1 from the openposition, a spring force accumulated in the arms 422 rises. This springforce reaches a peak immediately before the pressing portion 430breaches the upper surface of the substrate 2 and adds a spring forcewhich is slightly smaller than the peak value but greatly increased thanthat at the time of the open position to the upper surface of the slider430. Accordingly, the pressing portion 430b of the slider 430 is broughtinto press-contact with the upper surface of the substrate 2 by itsspring force, and simultaneously the terminals 4 of the bottom surfaceof the substrate 2 are brought into press-contact with the contactportions 421a of the contact pins 420. Then, after the pressing portion430b reaches the upper surface of the substrate 2, the slider 430further advances while holding the arms 422 at almost a constant degreeof opening, and therefore the pressing force applied to the slider 430is held almost constant.

As mentioned above, when there is a clearance between the substrate 2 ofthe IC chip 1 and a corner portion 411a of the socket body 411, afterthe side surface abutment portion 430a abuts against the side surface ofthe substrate 2 of the IC chip 1, the slider is further advanced exactlyby an amount of that clearance and the side surface of the substrate 2of the IC chip 1 can be pushed by the side surface abutment portion430a. Accordingly, it is possible to produce a wiping action in themovement direction, that is the front to rear direction of the slider430 between the terminals 4 of the IC chip 1 and the contact portions421a of the contact pins 420. This wiping action in the front to reardirection can be caused by reciprocation once each in the front and reardirection by individually moving the opposed two sliders 430.Accordingly, a more effective wiping action is obtained. Also, it ispossible to individually move the sliders 430 on the respective sideportions of the socket body 411, and therefore the operating forcerequired for the movement of the individual sliders 430 can be madesmall. Accordingly, it is possible to reduce the stress acting on the ICchip 1 and, at the same time, easily perform the attachment work of theIC chip 1 by a small force.

Further, in an IC socket 410 of the eighth embodiment, as shown in FIG.31 and FIG. 32, bent portions 421e projected to one side thereof areprovided in the base portions 421 of the contact pins 420, and aplurality of engagement members 430d engageable with the bent portions421e are provided on the lower surface of the slider 430. In thisembodiment, as shown in FIG. 32, the bent portions 421e of the contactpins 420 are alternately projected in opposite directions in an order ofthe arrangement of the contact pins 420. Also, engagement members 430dare arranged on both side surfaces of the base portions 421 of thecontact pins 420. The engagement members are determined to pass the bentportions 421e while resiliently displacing the base portions 421 of thecontact pins 420 to the side during a period when the pressing portion430b of the slider 430 reaches the upper surface of the IC chip 1 fromthe open position separated from the IC chip 1, and further advancesalong the upper surface, whereby the contact portions 421a of thecontact pins 421 and the terminals 4 of the IC chip 1 rub each other ina direction orthogonal to the movement direction of the slider 430, andtherefore a so-called wiping action of a left and right direction can beproduced between the contact portions 421e and the terminals 4.

Explaining in further detail the function of the engagement members 430dand the bent portions 421e, when the slider 430 is at the open position,as shown in FIG. 31(a) and FIG. 32(a), the engagement members 430d existbefore the bent portions 421e. When the slider 430d advances from theopen position and the pressing portion 430b reaches the upper surface ofthe substrate 2 of the IC chip 1, as shown in FIG. 31(b) and FIG. 32(b),the engagement members 430d reach the bent portions 421e. Thereafter,when the slider 430 further advances, as shown in FIG. 32(c), theengagement members 430d are engaged with the bent portions 420e of thecontact pins 420 and press the projection portion side thereof in thethickness direction, thereby to warp and resiliently displace thecontact pins 420 and displace the contact portions 421a of the contactpins 420 in the left and right direction, that is, in a directionsubstantially orthogonal to the movement direction of the slider 430.Then, as shown in FIG. 31(c) and FIG. 32(d), when the side surfaceabutment portion 430a of the slider 430 abuts against the side surfaceof the substrate 2 of the IC chip 1, since the engagement members 430dhave passed the bent portions 421e, the contact portions 421a of thecontact pins 421 return to the position before the displacement. In thisway, it is possible to resiliently displace the base portions 421 of thecontact pins 420 in the direction substantially orthogonal to themovement direction of the slider 430 to make the contact portions 421areciprocate one time during a period when the side surface abutmentportion 430a of the slider 430 abuts against the side surface of thesubstrate of the IC chip 1 after the pressing portion 430b of the slider430 reaches the upper surface of the substrate 2 of the IC chip 1. Then,during this time, the spring force of the arms 422 of the contact pins420 act on the upper surface of the substrate 2 of the IC chip 1 via theslider 430, and therefore the terminals 4 of the IC chip 1 and thecontact portions 421a of the contact pins 420 can be rubbed against eachother effectively under a required contact pressure in a directionorthogonal to the movement direction of the slider 430, and a so-calledwiping action in a left to right direction can be obtained. The amountof mutual rubbing between the contact portions 421a and the terminals 4of the IC chip 1 differs depending upon the contact pressure between theterminals 4 and the contact portions 421a, the shape of the tips of thecontact portions 421a, etc., but desirably it is about 0.05 mm or more.

Also, in the IC socket having the above-described configuration, theengagement members 430d of the slider 430 move in a state where theysandwich the base portions 421 of the contact pins 420 between twoengagement members 430d and pass through the bent portions 421e, andtherefore it is possible to warp and resiliently displace the baseportions 421 while defining the twist displacement of the base portions421 by two engagement members 430d. Accordingly, it is possible tofurther reliably produce a wiping action in a direction orthogonal tothe movement direction of the slider 430 between the contact portions421a of the contact pins 420 and the terminals 4 of the IC chip 1.

Also, the contact portions 421a of the contact pins 420 alternatelydisplace in opposite directions in an order of arrangement of thecontact pins 420 when the engagement members 430d pass through the bentportions 421e of the contact pins 420, and therefore it is possible toreliably prevent the IC chip 1 from moving following the movement of thecontact portions 421a of the contact pins 420. Accordingly, it ispossible to further reliably produce a wiping action between the contactportions 421a of the contact pins 420 and the terminals 4 of the IC chip1.

Further, when the sliders 430 are going to return to the open positionfrom the clamp position, the bent portions 421e of the contact pins 420abut against the engagement members 430d of the sliders 430, so act as astopper with respect to that return motion, and therefore it is possibleto prevent the IC chip 1 from carelessly being dropped from the socketbody 411.

FIG. 33 shows an insertion jig 432 for moving the sliders 430 from theopen position to the clamp position. When the guide posts 432a of theinsertion jig 432 are inserted into the positioning hole 411b of thesocket body 411, the inclined planes 432c provided in the leg portions432b of the jig 432 abut against the shafts 431 projected from theopposite ends in the length direction of the sliders 430, and when thejig 432 is further pushed down, the shafts 431 are pressed to an inwardside of the side portion of the socket body 411 by the inclined planes432c of the leg portions 432b, and therefore the sliders 430 can bemoved from the open position to the clamp position. Recesses 411f foraccommodating the leg portions 432b are formed in the socket body 411.

FIG. 34 shows a pull-out jig 433 for moving the slider 430 from theclamp position to the open position. The pull-out jig 433 is formed sothat the inclined planes 433c of the legs 433b abutting against theshafts 431 press against the shafts 431 in a reverse direction to thatfor the jig 432. The rest of the configuration is similar to the jig432. The guide posts 433a are inserted into the positioning holes 411bof the socket body 411 and pushed down, whereby the sliders 430 can beeasily moved from the clamp position to the open position.

As mentioned before, it is preferred if the bent portions 421e of thecontact pins 420 arranged at the respective side portions of the socketbody 411 are provided so as to project alternately in reversedirections, but it is also possible to make the bent portions 421e ofthe contact pins 420 project in the same direction at every sideportion. Note, in this case, if all of the bent portions 421e of thecontact pins 420 on the side portions are projected in the same left andright direction with respect to the movement direction of the sliders430, it becomes easy for the IC chip 1 to move in the clockwisedirection or the counterclockwise direction by the warp elasticdisplacement of the contact pins 420, and therefore, as schematicallyshown in FIG. 35, preferably the projection directions of the bentportions 421e are reversed for every side portion.

Moreover, it is also possible even if the bent portions 421e of thecontact pins 420 arranged on the respective side portions are reversedin their projection directions in units of groups comprising a pluralityof bent portions. Note, in this case, where the interval between thecontact pins is narrow, as shown in the same figure, preferably thepositions of the bent portions having different directions are madedifferent in the length direction of the contact pins 421.

Further, where the interval between the respective contact pins 420 isnarrow and, the bending directions of the bent portions 421e of theadjoining contact pins 420 differ, when the engagement members 430d ofthe sliders 430 are engaged with the bent portions 421e, there is anapprehension that the contact portions 421a of the adjoining contactpins 420 will come into contact with each other and if a power wereapplied to the contact pins 420 at the time of movement of the sliders430, a short-circuit would be caused. Therefore, as shown in FIG. 37, itis sufficient if fixing portions 411g sandwiching the base portions 421of the contact pins 420 between the bent portions 421e and the contactportions 421 of the contact pin 420 be provided in the socket body 411.If such fixing portions 411g exist, the amount by which the contactportions 421a can resiliently displace in the thickness direction of thecontact pins is restricted, and it is possible to prevent the contactportions 421a of adjoining contact pins 421 from coming into contactwith each other.

FIG. 38 shows a ninth embodiment of the present invention resembling theeighth embodiment. In the figure, constituent elements similar to thoseof the eighth embodiment are given the same references. In the IC socketof this ninth embodiment, a support leg 421f extended downward frombetween the contact portion 421a and the bent portion 421e and supportedat the lower end portion by the socket body 411 is provided in the baseportion 421 of each contact pin 420. In this embodiment, since the lowerend portion of the support leg 421f positioned between a contact portion421a and a bent portion 421e of the contact pin 420 is supported by thesocket body 411, when an engagement member 430d of the slider 430 passesthe bent portion 421e of the contact pin 420 and the base portion 421 ofthe contact pin 420 is resiliently displaced to the side, the contactportion 421a of the contact pin 420 can easily warp and resilientlydisplace to the side of the contact pin 420, that is, in the thicknessdirection with the lower end portion of the support leg 421f as thesupport point. Namely, where the support leg 421f does not exist, whenthe engagement member 430d of the slider 430 passes the bent portion421e of the contact pin 420, it can be considered that the contactportion 421a of the contact pin 420 having come into press-contact withthe bottom surface terminal 4 of the IC chip 1 acts as the support pointand the base portion 421 of the contact pin 420 twists and resilientlydisplaces. Then, when such a twist elastic displacement occurs, itbecomes impossible to obtain the wiping action in the contact portion421a of the contact pin 420. Contrary to this, when the lower endportion of the support leg 421f positioned between the contact portion421a of the contact pin 420 and the bent portion 421e is supported bythe socket body 411, the above-described twist elastic displacement issuppressed, it is possible to easily make the contact portion 421a ofthe contact pin 420 warp and resiliently displace to the side, that is,in the thickness direction. Accordingly, it is possible to reliablyproduce a wiping action in a direction substantially orthogonal to themovement direction of the slider 430 (left and right direction) betweenthe contact portion 421a of the contact pin 420 and a terminal 4 of theIC chip 1.

FIG. 39 shows a 10th embodiment of the present invention resembling theeighth embodiment. In the figure, constituent elements similar to thoseof the eighth embodiment are given the same references. In the IC socketof the eighth embodiment, the arm 422 of the contact pin 420 constitutesthe spring means, but in the IC socket of the 10th embodiment, thespring plate 434 pressing against the upper surface of the slider 430 isformed separately from the contact pin 420 and fixed on the socket body411. Where a spring plate 434 separately provided from the contact pin420 is used in this way, it is possible to separate the spring plate 434covering the upper surface of the slider 430 to a state nonconductive tothe contact pin 420, and therefore it is possible to prevent the risk ofshort-circuiting of the contact pins 420 due to a dropped object, etc.Moreover, it is also possible to utilize the upper surface of the springplate 434 as the display portion of the product name, mold number, etc.,which is convenient.

Note that, the spring plate 434 of the illustrated embodiment isconstituted by one plate, but it is also possible to arrange a pluralityof plate materials in parallel in an arrangement direction of thecontact pins 420 to constitute the spring plate 434. When the springplate 434 is constituted by a plurality of plate materials, even if theslider 430 or the spring plate 434 has a corrugated shape, it ispossible to prevent a situation wherein the slider 430 and the springplate 434 come into contact only by one part. Also, even if the springplate 430 is constituted by one plate, a plurality of notches areprovided in the end portion on the pressing portion 430b side of theslider 430 to make a substantially comb-like shape, whereby it ispossible to prevent a situation wherein the slider 430 and the springplate 434 come into contact only by one part.

FIG. 40 shows an 11th embodiment of the present invention resembling theeighth embodiment. In the figure, constituent elements similar to thoseof the eighth embodiment are given the same references. In thisembodiment, similar to the fourth embodiment of FIG. 10, a rack 430e isformed in the slider 430. At the same time, a rack 435a opposed to therack 430e of the slider 430 is formed in the stationary member 435, anda pinion 436 engaged with the racks 430e and 435a is provided betweenthe slider 430 and the rack 430e. A lever 437 for operation is fixed onone end portion or both end portions of the pinion 436. When the pinion436 is rotated by operating this lever 437, the pinion 436 moves theslider 430 while pivoting on the rack 435a of the stationary member 435.Accordingly, in this embodiment, the slider 430 can be easily movedwithout the use of a jig as shown in FIG. 33 and FIG. 34.

FIG. 41 through FIG. 43 show a 12th embodiment of the IC socketaccording to the present invention.

Referring to these figures, the IC socket 510 of the 12th embodiment isprovided with a frame-shaped socket body 511 having a generallyrectangular configuration, a plurality of contact pins 521 which arearranged in parallel to each other along the sides of this socket body511 so as to form rows, and pivot cams 522 a half of which beinginserted into an internal space of a substantially horizontal U-shapeformed by the contact pins 521 arranged along the respective sides ofthe socket body 511 and forming rows.

Each contact pin 521 has a base portion 521A and an arm 521B. The baseportion 521A of each contact pin 521 has a lower horizontal portion 521aextended substantially horizontally along the side of the socket body511, an inclined portion 521c extended inclined upward toward the insideof the socket body 511 from one end of the lower horizontal portion521a, and an upper horizontal portion 521d extended substantiallyhorizontally toward the inside of the socket body 511 from an upper endof the inclined portion 521c. On one end of the base portion 521A ofeach contact pin 521, that is, on the tip of a second horizontal portion521d, an upward contact portion 521b for coming into contact with aterminal arranged on the bottom surface of the IC chip substrate 2(illustration is omitted) is formed. Also, an external connectingportion 521e for electrical connection to the external circuit board isformed on the other end of the base portion 521A of each contact pin521, that is, on the other end of the lower horizontal portion 521a.Further, a leg portion 521f projected downward from the lower horizontalportion 521a is provided in the base portion 521A of each contact pin521, and slits 511a into which leg portions 521f of contact pins in therows 521 are inserted and grooves 511e into which the contact portions521b of the contact pins 521 are inserted are respectively provided inparallel on each side of the socket body 511 so as to form rows. Byengagement between these slits 511a and grooves 511e, contact pins inthe rows 521 are defined in their position with respect to the socketbody 511.

The arm 521B of each contact pin 521 has a curved portion 521i extendedcurved upward and outward from the first horizontal portion 521a of thebase portion 521A, and a horizontal portion 521g extended almost inparallel to the first horizontal portion 521a of the base portion 521Afrom the upper end of the curved portion 521i. On the tip of thehorizontal portion 521g, that is, on the tip of the arm 521B, a downwardinclined almost circular engagement portion 521h positioned almost abovethe inclined portion 521c of the base portion 521A is formed. At thesubstantial center of the upper surface of the pivot cam 522, anengagement groove 522a which has a cross-sectional shape adapted to theengagement portion 521h of the arm 521B and extended along the wholelength of the pivot cam 522 is formed. The engagement portions 521h ofthe arms 521B of the contact pins in the rows 521 are engaged with theengagement grooves 522a of the pivot cam 522, whereby the pivot cam 522can pivot between an open position of a standing posture shown in FIG.41(a) and a pressing position of substantially a horizontal postureshown in (b) of the same figure with the engagement portion 521h of thearm 521B as the pivot support point. At the open position, the pivot cam522 has retracted from the insertion region of the IC chip substrate 2,and at the pressing position, the pivot cam 522 can press against theupper surface and side surface of the IC chip substrate 2.

Further, the pivot cam 522 has a first contact portion 522b whichresiliently comes into contact with the inclined portion 521c of thecontact pin 521 when the pivot cam 522 is located at the open position,a second contact portion 522c which resiliently comes into contact withthe inclined portion 521c of the contact pin 521 when the pivot cam 522is located at the pressing position, and an inclined portion 522iextended toward the tip of the pivot cam 522 from the second contactportion 522c. Further, on the tip of the pivot cam 522, a side surfaceabutment portion 522d for abutting against the side surface of the ICchip substrate 2 and an upper surface abutment portion 522e for abuttingagainst the upper surface of the IC chip substrate 2 are formed.

A plurality of ribs 522f for limiting the arms 521B of the contact pinsin the rows 521 to the same intervals are provided in the engagementgrooves 522a of the pivot cams 522, and the ribs 522f are arrangedbetween the engagement portions 521h of the adjoining contact pins 521.Also, a plurality of ribs 522h for limiting the base portions 521A ofthe contact pins in the rows 521 to the same intervals are provided inthe pivot cams 522. Each rib 522h is arranged between the inclinedportions 521c of the base portions 521A of the adjoining contact pins521 and continuously extended to above the first contact portions 522b,second contact portions 522c and the inclined portions 522i of the pivotcams 522. Accordingly, some of the ribs 522h are always positionedbetween the inclined portions 521c of the adjoining contact pins 521during the pivoting of the pivot cams 522. Since the ribs 522h arearranged at positions where the pivot cams 522 and the base portions521A of the contact pins 521 come into elastic contact with each other,even ribs 522h having a low height can sufficiently act to define theintervals of the base portions 521A.

One or a plurality of projection pieces 522g projected from the tips ofthe pivot cams 522 are provided. The projection pieces 522g can bearranged at the centers or end portions of the lengths of the pivot cams522. By operating the projection pieces 522 by a finger, it is possibleto easily pivot the pivot cams 522.

Next, an operation of the IC socket of the 12th embodiment will beexplained.

First, when the pivot cams 522 are pivoted to the standing open positionas shown in FIG. 41(a), the first contact portions 522b of the pivotcams 522 comes into elastic contact with the inclined portions 521c ofthe contact pins 521, whereby the pivot cams 522 are stably held at theopen position. At the open position, a part positioned on the inclinedportions 522i among the ribs 522h of the pivot cams 522 is inclined andis useful as a guide facilitating the insertion of the IC chip substrate2.

After the IC chip substrate 2 is placed on the contact portions 521b ofthe contact pins 521, the projection pieces 522g of the pivot cams 522are operated by the finger, and as shown in FIG. 41(b), the pivot cams522 is pivoted to substantially a horizontal pressing position. At thepressing position, the pivot cams 522 between the engagement grooves522a and the second contact portions 522c are resiliently pressed andsandwiched between the engagement portions 521h and the inclined planes521c of the contact pins 521. At this time, the second contact portions522c are positioned on the outside of the engagement grooves 522a, andtherefore the pivot cams 522 are urged by the arms 521B of the contactpins 521 so that the pressing portions 522e are pressed downward.Accordingly, the IC chip substrate 2 can be pressed downward.

Where the IC chip substrate 2 is to be removed from the socket body 511,it is sufficient if a reverse operation to that mentioned above iscarried out, and therefore an explanation will be omitted.

In the 12th embodiment, as shown in FIG. 42, the pivot cams 522 havelengths up to the opposite ends of the rows of the contact pins 521. Itis also possible to hold a plurality of divided pivot cams in the rowsof the contact pin 521 as shown in FIG. 43 instead of the above. In thiscase, the pivoting operation of the divided pivot cams becomes furthereasy, and therefore it is preferred for a case where the number of thecontact pins 521 forming the rows is large.

As mentioned above, in the IC socket 510 of the 12th embodiment, theprojections 522g may be operated by the fingers to operate the contactpins 521, and therefore special additional equipment such as aninsertion jig, a pull-out jig, etc. are unnecessary.

Also, it is possible for the pivot cams 522 to pivot over the wholelengths thereof exactly by the same angles, and therefore a twist doesnot occur, and accordingly the contact pins 521 change with completelythe same shape at the opposite end portions and the center portions.Accordingly, it is possible to increase the number of the contact pins521.

Further, the operation of the pivot cams 522 consists only of raising orlowering the extended pieces 522g, and therefore a pressing force fromabove is not given to the socket, and even in a case of mounting on alarge size substrate or a thin substrate, there is no apprehension ofwarping or damage of the substrate.

FIG. 44 to FIG. 48 show a 13th embodiment of the socket assemblyaccording to the present invention.

Referring to these figures, a chip-on-board module 1 is provided with asubstrate 2 and a circuit part 3 such as an IC chip etc. mounted on thesubstrate 2 (refer to FIG. 44 ). On the bottom surface of the substrate2, a plurality of pads 4 acting as terminals are arranged at narrowintervals along four edges of the bottom surface so as to form rows. Thesocket, shown overall by the reference 610, is designed so as toelectrically connect the module 1 to the circuit board 5.

The socket 610 is provided with a socket body or a support frame 611made of an insulating material such as a plastic. The support frame 611has a generally rectangular configuration so as to surround theperiphery of the substrate 2 of the module 1, and a plurality of contactpins 612 made of metal are carried on the support frame 611 so as toform four rows in the form of a rectangle. Each contact pin 612 has anupward contact portion 612a for contact with a pad 4 of the module 1 onone end and has a base portion 612A having an external connectingportion for connection to the conductor pattern 6 of the printed circuitboard 5 or lead portion 612b and an arm 612c having a spring property onthe other end. The constitution is made so that the four edges of thebottom surface of the substrate 2 of the module 1 can be respectivelysupported by the contact portions 612a of the four rows of the contactpins 612. The lead portion 612b of each contact pin 612 is extendedalong the mounting surface of the circuit board 5, and as shown in FIG.44 and FIG. 46, is soldered onto the conductor pattern 6 formed on themounting surface by reflow in two sections S1 and S2. The arm 612c ofeach contact pin 612 is positioned inside the support frame 611 andcomprises a curved part rising upward while curving to the inside of thesupport frame 611 from an intermediate portion of the lead portion 612band a straight part substantially straightly extended from the upper endof this curved part toward the inside of the support frame 611. As seenfrom FIG. 44 and FIG. 45, a space for accommodating the module 1 isdefined by the tip of the straight parts of the arms 612c of the fourrows of contact pins 612. Each of the contact pins 612 further has aprojection portion 612d projected upward from the lead portion 612b onthe outside of the support frame 611. A plurality of ribs 611a and 611brespectively extended in a vertical direction are provided inside andoutside of the support frame 611 so as to form rows. The curved partsand projection portions 612d of the arms 612c of the contact pins in therows 612 are disengageably engaged between the respectively adjoiningribs 611a and 611b on the inside and outside of the support frame 611.As easily understood from FIG. 44, the support frame 611 can be removedupward from the contact pins 612 soldered to the circuit board 612.

As shown in FIG. 45 and FIG. 47, at the four corner portions of thesupport frame 611, engagement holes 611c opened in the upper surfacethereof are formed. After the contact pins 612 are soldered onto thecircuit board 5, the module 1 is mounted on the contact portions 612a ofthe contact pins 612, but where the module 1 is mounted by an automaticfeeder, the positioning pins provided in the automatic feeder areengaged with the engagement holes 611c of the support frame 611, wherebythe positioning of the module 1 and the contact pins 612 can be easilycarried out.

The socket 610 is further provided with four sliders 613 forindividually pressing the edges of the upper surface of the substrate 2of the module 1 against the contact portions 612a of the contact pins612. The sliders 613 are held between the lead portions 612b and thearms 612c of the rows of contact pins 612 inside the support frame 611,and the opposite end portions of the slider 613 are projected from theopposite ends of the rows of the contact pins 612. The sliders 613 havepressing portions 613a pressing against the edges of the substrate 2 ofthe module 1. In further detail, the pressing portions 613a of thesliders 613 comprise upper surface pressing portions pressing againstthe upper surface of the substrate 2 of the module 1 and end surfacepressing portions pressing against the end surfaces of the substrate 2of the module 1. The slider 613 shown in FIG. 44 is at a pressingposition for pressing the edge of the module 1 against the contactportions 612a of the contact pins 612 by the spring force of the arms612c of the contact pins 612, and the slider 613 shown in FIG. 46 islocated at the open position for releasing the module 1 from the contactpins 612. The sliders 613 can be moved between the pressing positionshown in FIG. 44 and the open position shown in FIG. 46 along the uppersurfaces of the lead portions 612b of the contact pins 612 by a jigengaged with the opposite ends thereof (not illustrated). When thesliders 613 move from the open position to the pressing position, thearms 612c are warped upward by the sliders 613 to generate the pressingforce. During a period when the sliders 613 move from the open positionto the pressing position, the spring force of the arms 612c is increasedby the upper surface shape off the lead portions 612b and reaches a peakimmediately before the sliders 613 reach the pressing position, andthereafter the spring force is slightly lowered from the peak valueuntil the sliders 613 reach the pressing position.

The sliders 613 are provided with a plurality of lower partition walls613b for engaging with the lead portions 612b of the rows of contactpins 612 and upper partition walls 613c engaging with the arms 612 ofthe contact pins 612. These partition walls 613b and 613c perform therole of holding the rows of contact pins 612 at predetermined intervalsat all times. The sliders 613 preferably are formed by a substance witha poor wettability with respect to solder, for example, polyether imide,polyphenylene sulfide, polyester sulfone, etc. As will be understoodfrom FIG. 46, the lower partition walls 13b of the sliders 613 extend soas to cover all of the portions located above the soldered sections S1in the sliding sections between the lower partition walls 613b and thecontact pins 612. Accordingly, when soldering the contact pins 612 onthe circuit board 5, it is possible to prevent the melted solder fromadhering to the sliding sections between the lower partition walls 613band the contact pins 612.

In the socket 610 having the above configuration, after a module 1 ismounted on the contact portions 612a of the rows of contact pins 612, itis possible to move the sliders 613 from the open position to thepressing position so as to press the four edges of the substrate 2 ofthe module 1 individually against the contact portions 612a of thecontact pins 612 by the four sliders 613. Accordingly, there is no needfor ensuring a pressing force enough for enabling contact between allthe pads 4 of the module 1 and the contact portions 612a of all thecontact pins 612 in a single slider 613. It is sufficient so long asenough of a pressing force for enabling contact of one row of pads 4 andthe contact portions 612a of one row of contact pins 612 by a requiredcontact pressure can be ensured. Accordingly, it is possible to reducethe force required for the movement operation of the sliders 613, soattachment and detachment work of the modules becomes easy. Further,since the sliders 4 press the edges of the substrate 2 of the module 1against the contact portions 612a of the rows of contact pins 612, forexample, even if there is some variation in the spring force of the arms612c of the contact pins 612, it is possible to make uniform the contactpressure between the contact portions 612a of the row of contact pins612 and the row of pads 4 and thereby to improve the reliability ofconduction. Further, it is possible to successively press the oppositeedges of the substrate 2 of the module 1 by two opposing sliders 613, soit is possible to finely move the substrate in the direction of movementof the sliders 613 in a state where the sliders 613 press against thetop surface of the substrate 2 of the module 1. Accordingly, it ispossible to cause a wiping action between the pads 4 of the module 1 andthe contact portions 612a of the contact pins 612 and possible toimprove the reliability of electrical connection. Further, in the caseof this embodiment, the sliders 613 move from the open position to thepressing position while pressing apart the ribs 612b and arms 612c ofthe contact pins 612, whereby the arms 612a of the contact pins 612 aremade to move upward and an increased spring force is generated.Accordingly, by designing the contact pins 612 and the sliders 613 so asto increase the amount of movement of the sliders 613 from the openposition to the pressing position, it is possible to move the sliders613 from the open position to the pressing position with a light forcewhile moving the arms 612c upward and therefore the operability of thesliders 613 can be improved.

Further, the support frame 611 is engaged with the contact pins 612 atthe side of the contact pins 612 opposite to the portions soldered tothe circuit board 5 to enable detachment from the contact pins 612 afterthe lead portions 612b of the contact pins 612 are affixed to thecircuit board 5 by soldering, so the mounting height of the contact pins2 themselves with respect to the circuit board 5 becomes smaller and itis possible to make the mounting height with respect to the circuitboard 5 of the module 1 mounted on the contact pins 612 smaller.

Further, it is possible to solder the contact pins 612 on the circuitboard 5 and then leave the support frame 611 on the contact pins 612,but the support frame 611 and the contact pins 612 are detachablyengaged by the elasticity of the two, so it is possible to pull out thesupport frame 611 from the contact pins 612 in accordance with need.Accordingly, by soldering the contact pins 612 to the circuit board 5and then pulling out the support frame 611 from the contact pins 612,the socket 610 can be made further lighter in weight. Preferably, thethickness of the support frame 611, as illustrated, is set so that theheight from the circuit board 5 to the top surface of the support frame611 becomes substantially equal to the height of the contact pins 612 orshorter than the height of the contact pins 612. By this, it is possibleto prevent an increase in the mounting height of the socket 610 even ifthe support frame 611 remains on the contact pins 612.

Further,the rows of contact pins 612 are soldered to the circuit board 5in the state supported by the support frame 611, so this prevents thereduction of the efficiency of soldering work and the precision ofposition of the contact pins 612 with respect to the circuit board 5.

Further, since the rows of contact pins 612 are detachably engagedbetween the adjoining ribs 611a and 611b at the inside and outside ofthe support frame 611, the rows of contact pins 612 can be held atpredetermined intervals by the ribs 611a and 611b at the inside andoutside of the support frame 611 and can be positioned and affixed in adirection cutting across the support frame 611. Accordingly, the rows ofcontact pins 612 can be soldered on the circuit board 5 with a highprecision of positioning.

FIG. 49 shows the 14th embodiment of the socket assembly according tothe present invention. In this 14th embodiment, the section positionedabove the soldered section S1 in the sliding region of the contact pins612 which slide with the lower partition wall 613b of the slider 613b iscovered with a substance 614 with a poor wettability with solder, thatis, resistant to deposition of solder. The rest of the configuration issimilar to that of the above 13th embodiment. Accordingly, it ispossible to prevent deposition of solder at the sliding region of thecontact pins 612 with the lower partition wall 613b of the slider 613.

FIG. 50 and FIG. 51 show a 15th embodiment of a socket assemblyaccording to the present invention.

Referring to these drawings, in the socket 610 of the 15th embodiment,the support frame has attached to it in a detachable manner a cap 615 ofthe module 1. Like with the support frame 611 of the 13th embodiment,engagement holes (not shown) opening to the top surface are formed atthe four corner portions of the support frame 611 of the 15thembodiment. At the bottom of the cap 615, engagement pins 615a whichengage detachably with the engagement holes of the support frame 611 aremade. Further, the cap 615 has formed on it the ribs 615b for definingthe intervals of the arms 612c of the rows of the contact pins 612 andthe opening 615c for enabling visual observation of the contact portions612a of the contact pins 612 from above. The rest of the configurationis similar to that in the 13th embodiment.

In the socket 610 of the 15th embodiment, the cap 615 covering the areaabove the module mounting region of the contact pins 612 is attacheddetachably to the support frame 611, so it is possible to ensure a widesuction surface for a suction type socket feeder at the top surface ofthe cap 615. Accordingly, the automatic feed of sockets 610 to thecircuit board 5 by a socket feeder can be easily and swiftly performed.Furthers, the the cap 615 can be removed from the support frame 611after the contact pins 612 are soldered to the circuit board 5, so it ispossible to mount the module 1 on the contact portions 612a of thecontact pins 612 without problem. Further the support frame 611 can beleft on the circuit board 5, so it is possible to use the support frame611 to easily and quickly position the module 1 and contact pins 612 bya part feeder.

Further, it is possible to solder the contact pins 612 on the circuitboard 5 in a state where the contact pins in the rows 612 are morereliably defined in position by the ribs 611a and 611b of the supportframe 611 and the ribs 615b of the cap 615. Further, the cap 615 isformed with an opening 615c for enabling visual observation of thecontact portions 612a of the contact pins 612 from above, so whenmounting the socket 610 on the circuit board 5 by an automatic feeder,it is possible to easily and quickly position the contact pins 612 andthe circuit board 5 while observing the positions of the contact pins612 and circuit board 5 by a CCD camera etc. through the opening 615c ofthe cap 615.

FIG. 52 shows a 16th embodiment of a socket assembly according to thepresent invention. The socket of the 16th embodiment differs from thatof the 15th embodiment in the point that the cap 615 for covering thetop surface of the module 1 is provided integrally with the supportframe 611. In the 16th embodiment, the support frame 611 can be pulledout from the contact pins 612 together with the cap 615 after thecontact pins 612 have been soldered to the circuit board 5.

FIG. 53 shows a 17th embodiment of the present invention in which achange is made to the sliders 613 held by the rows of contact pins 612.Note that the illustration of the support frame is omitted in FIG. 53.The four sliders 613 in the 17th embodiment are formed so that the endsabut against each other in the pressing position. Accordingly, it ispossible to prevent the sliders 613 from moving excessively over thepressing position from the open position. The rest of the configurationis similar to that of the 13th embodiment, but the support frame of the17th embodiment is formed so as to surround the vicinity of the foursliders 613. Note that the support frame of the 17th embodiment, likethe above 13th embodiment, can be pulled out from the contact pins 612after soldering the contact pins 612 to the circuit board 5 or attachingthe module 1 on the contact portions 612a of the contact pins 612 by thesliders 613, but may also be left on the contact pins 612.

FIG. 54 to FIG. 57 show an 18th embodiment of a socket for an electricalcomponent according to the present invention, which is suitable for thecase of pulling out the support frame from the contact pins aftersoldering of the contact pins. FIG. 54 shows the state of mounting ofthe module 1 on the circuit board 5 through the socket 610 attached tothe circuit board 5, while FIG. 55 shows the step of attaching thecontact pins 612 to the circuit substrate 5 by soldering. Further, FIG.56 shows the arrangement of the contact pins 612 and sliders 613 whenthe sliders 613 are in the pressing position. FIG. 57 shows thearrangement of the contact pins 612 and sliders 613 when the sliders 613are in the open position. FIG. 58 shows the metal plate 616 forproducing the contact pins in the rows 612. By punching the metal plate616, contact pins 612 connected to each other at the opposite ends areformed.

The rows of contact pins 612 in the 18th embodiment, like in the 13thembodiment, are soldered on the circuit board 5 in the inside solderingsection S1 and the outside soldering section S2, but the pitch and widthof the portion of the outside soldering section S2 of the lead portions612b are larger than the pitch and width of the contact portions 612a.Further, the rows of contact pins 612, as will be understood from FIG.54 and FIG. 55, are formed by simultaneous punching and simultaneousbending of a single sheet of metal plate 616 shown in FIG. 58.Accordingly, the arms 612c of the contact pins are extended connectedfrom the contact portions 612a. Further, in the vicinity of the outsidesoldering section S2 of the lead portions 612b, resilient portions 612eare formed projecting upward. At the inside surface of the support frame611 integral with the cap 615, ribs 611c engaging detachably with theresilient portions 612e of the rows of contact pins 612 in the verticaldirection. Further, the cap 615 is formed with a wall 615d whichcooperates with the support frame 611 to grip the resilient portions612e of the contact pins 612. The sliders 613 held by the rows ofcontact pins 612, like the sliders of the 17th embodiment, are formed sothat the opposite ends abut against other ends at the pressing positionshown in FIG. 56.

Note that the cap 615 of the 18th embodiment is formed integrally withthe support frame 611, so it is necessary to withdraw the support frame611 from the contact pins 612 after soldering the contact pins 612 onthe circuit substrate 5, but it is also possible to allow the supportframe 611 to remain on the contact pins 612 by forming the cap 615separate from the support frame 611 and attaching it detachably to thesupport frame 611 or omitting the cap.

In the socket 610 of the 18th embodiment, the pitch and width of theportion of the external soldered section S2 of the lead portions 612b ofthe row of contact pins 612 are larger than the pitch and width of thecontact portions 612a, so contact and conduction with the module pads 4with their fine pitches are possible without detracting from the bondingstrength of the rows of contact pins 612 and the circuit substrate 5.

Further, since the rows of contact pins 612 are formed by simultaneouslypunching and simultaneous bending of a single sheet of metal plate 616,contact pins 612 partially different in pitch and pin width can beeasily obtained. Still further, it is possible to hold the rows ofcontact pins 612 formed by the simultaneous bending of a single metalsheet 616 simultaneously by a support frame 611 and then cut the rows ofcontact points 612 completely from each other, so the socket becomesextremely easy to manufacture.

The sockets of the 13th to 18th embodiments may be used for electricalconnection between lead-less IC packages or lead IC packages and otherelectrical components with the circuit substrate.

FIG. 59 to FIG. 66 explain the 19th embodiment of the IC socket assemblyaccording to the present invention.

First, referring to FIG. 59 to FIG. 61, the socket body or base plate712 of the IC socket 710 is made of plastic and has a generallyrectangular configuration. The base plate 712 is provided with guidecylinders 712a at the four corners. Further, each side of the base plate712 is provided with two through holes 712b and a groove 712. The ICpackage 1 mounted in the IC socket 710 has terminals (lands or pads)arranged forming rows on the top surface of the substrate 2 along thesides of the substrate 2. At the sides of the substrate 2 of the ICpackage 1, the terminals 4 may be extended connected along the topsurface, side surface, and bottom surface of the substrate 2. Some ICpackages have terminals arranged only at two opposite sides. When usingan IC socket exclusively for such IC packages, it is sufficient toprovide the configuration explained below at just the two oppositesides.

The base plate 712 is formed with ribs 712d sandwiching the grooves 712cat its two sides at the top surface as will be understood from FIG. 60and FIG. 61. The ribs 712d may be formed further at just the inside sideof the grooves 712c or at the side of the base plate 712. One more setof the ribs 713d than the number of contact pins is provided and thesets are arranged in parallel at predetermined intervals from each otheralong the sides of the base plate 712. Further, the base plate 712 isprovided with receiving portions 712e defining the four corners of thesubstrate 2 of the IC package 1 as shown in FIG. 59.

The plastic sliders 713 are attached to the base plate 712 through thelater mentioned contact pins. The sliders 713 have attached to themmetal shafts 714, but if there is no concern over wear or deformationdue to temperature, then the shafts 714 may be made of a plastic andformed integrally with the sliders 713. The sliders 713, as will beunderstood in FIG. 60 and FIG. 61, are formed with the step portions713a as the first position restricting portions, the inclined portions713b as the second position restricting portions, and the engagementportions 713c. Further, they have flat side surfaces 713d.

Further, the sliders 713, as shown in FIG. 60, are formed with the ribs713e at the top surface. Further, they are formed with ribs 713e at thesame cross-sectional positions at the bottom surface. One more set ofthe ribs 713e than the number of contact pins is provided and the setsare arranged in parallel at predetermined intervals from each otheralong the sides of the base plate 712.

The configuration of the contact pins 715 in this embodiment will beexplained using mainly FIG. 60. The attachment portions 715a of thecontact pins 715 are press-fit between two adjoining ribs 712d in thegrooves 712c of the base plate 712. At one end of each of the contactpins 715, an external connection terminal 715b for connection with theprinted circuit board is formed. At the other end, a contact portion715c for pushing the substrate 2 of the IC package 1 upward andcontacting a terminal 4 of the IC package 1 is formed. Between these areformed a first spring portion 715d and a second spring portion 715e.Further, the tip of an extension portion 715h extending from between theexternal connection terminal 715b and the first spring portion 715dcontacts the bottom of the substrate 2 and supports the IC package 1.Further, between the contact portion 715c and the second spring portion715e, there are formed abutting portions 715f and 715g which are pressedby the engagement portion 713c of the slider 713.

The first spring portion 715d is given a substantially downward biasforce, while the second spring portion 715e can be given a bias forcesubstantially in the left-right direction. Accordingly, in FIG. 60, thefirst spring portion 715d presses against the inclined portion 713b ofthe slider 713. In so far as no special strong force is applied from theoutside, this limits the movement of the slider 713 in the left-rightdirection. In this embodiment, a plurality of contact pins 715 of thisconfiguration are provided between two ribs 712d provided on the baseplate 712 and two adjoining ribs 713e provided on the slider 713 andattach the slider 713 with respect to the base plate 712 movable in thehorizontal direction.

Next, an explanation will be made of an example of a jig for moving thesliders 713 by outside force using FIG. 62 and FIG. 63. The jig 716shown in FIG. 62 is rectangular overall in the same way as the baseplate 712. Its important parts are at the four corners. Further, eachcorner has the same configuration. Therefore, the relationship with thebase plate 712 will be clarified and shown for just one corner. The jig716 is comprised of guide pins 716a which fit with the guide cylinders712 and actuating pins 716b formed with inclined cut portions at theirtips.

FIG. 63 similarly shows another jig 717. This is comprised of guide pins717a which fit with the guide cylinders 712a and actuating pins 717bformed with inclined cut portions at their tips. The point of differenceof the two jigs 716 and 717 is that the directions of inclination of thecut portions formed at the tips of the actuating pins 716b and 717b arereverse in direction. That is, the actuating pin 716b shown in FIG. 62moves downward and engages with the shaft 714 at its tip, whereby itmoves the shaft 714, that is, the slider 713, in the inward direction ofthe base plate 712, while the actuating pin 717b shown in FIG. 63conversely moves the shaft 714 in the outward direction of the baseplate 712.

Next, the operation for mounting the IC package 1 will be explainedusing FIG. 64, FIG. 65, and FIG. 66. FIG. 64 shows the state ofattachment or detachment of the IC package. It shows the state ofinsertion of the IC module 1 into the accommodating space of the ICsocket and mounting there. FIG. 60 shows the state of completion ofmounting, while FIG. 65 and FIG. 66 show the states in the middle of theprocess from the state of FIG. 64 to the state of FIG. 60.

First, FIG. 64 shows the state of movement of a slider 713 to the left.The engagement portion 713c pushes the abutting portion 715f to flex thesecond spring portion 715e from the neutral position to the left andcause the contact portions 715c to retract to the left to give the statewhere the IC package 1 can be freely attached and detached. The slider713 is defined in position by friction by the first spring portion 715dengaging with the step portion 713a and being pushed downward.Accordingly, the slider 713 never moves in the horizontal direction dueto normal vibration etc., but if if necessary, it is possible to form aprojection at one of the first spring portion 715d and the step portion713a and a recess at the other to form a so-called clip-stoppingarrangement. FIG. 64 shows the state in which the slider 713 is limitedin position in this manner. The IC package 1 is inserted into theaccommodating space from above by hand or an automatic machine and isplaced on the extension portions 715h of the contact pins 715 in thestate shown.

In the state of FIG. 64, if the insertion jig 716 shown in FIG. 62 ispushed down manually or by an automatic machine while the guide pins arebeing guided 716a by the guide cylinders 712a, the actuating pins 716bpush the shafts 714 projecting out from the opposite ends of the sliders713 to the side directions. Due to this, the sliders 713 are moved tothe inside, that is, to the IC package 1, and reach the position of FIG.65. At the position of FIG. 65, the engagement portions 713c of thesliders 713 are in a non-pressing state with respect to the secondspring portions 715e and the second spring portions 715e return to theneutral position. Further, the contact portions 715c of the contact pins715 are at a position up away from the top surface of the substrate 2 ofthe IC package 1.

If the sliders 713 are further moved, the first spring portions 715dengage with the inclined portions 713b from the step portions 713a dueto the spring force. FIG. 66 shows the initial state at which the firstspring portions 715d engage with the inclined portions 713d. In thestate of FIG. 66, the first spring portions 715d move downward from eventhe position show in FIG. 65, so the contact portions 715c contact theterminals 4 disposed at the side of the top surface of the substrate 2of the IC package 1. On the other hand, the engagement portions 713c ofthe sliders 713 are at positions contacting the abutting portions 715g,the second spring portions 715e are at neutral positions, and the sidesurfaces 713c of the sliders 713 still do not abut against the sidesurfaces of the substrate 2 of the IC package 1.

At the position shown in FIG. 66, the contact portions 715c and theextension portions 715h grip the substrate 2 of the IC package in thevertical direction and the contact portions 715c contact the terminals 4provided on the substrate 2 of the IC package, so the IC package 1 andthe contact pins 715 are electrically connected in state. Accordingly atthis time, the first spring portions 715d may be made to engage with theflat portions at the bottom steps after the inclined portions 713b ofthe sliders 713. In this case, the flat portions of the bottom stepsbecome the second position controlling portions. If there isapprehension over the ability to control the position, as mentionedearly, clipping is possible. Further, in the 19th embodiment, the topsurfaces of the sliders 713 are formed with two steps at the top andbottom through a step difference, but it is not absolutely necessary toprovide such a step difference. For example, the shape of the topsurfaces of the sliders 713 and the shape of the first spring portions715d may be made as shown in FIG. 67. In this case the recesses 713f ofthe sliders 713 become the second position defining portions.

Further, in the 19th embodiment, the sliders 713 are moved further tothe right from the position of FIG. 66. The position shown in FIG. 60 ismade the pressing position of the sliders 713, that is, the position ofcompletion of mounting of the IC package 1. In this way, if the sliders713 are moved from the position of FIG. 66 further to the right, thefirst spring portions 715d of the contact pins 715 will descend alongthe inclined portions 713b of the sliders 713. Accordingly, the contactpressure of the contact portions 715c on the terminals 4 at the topsurface of the substrate 2 of the IC package 1 will increase. Further,since the engagement portions 713c of the sliders 713 press against theabutting portions 715g of the contact pins 715, the second springportions 715e are moved from the neutral position against theelasticity. Therefore, the contact portions 715c of the contact pins 715slide with respect to the surfaces of the terminals 4 of the top surfaceof the substrate 2 and cause so-called wiping action. Accordingly, evenif an oxide film is formed on the surfaces of the terminals 4 or dust orother dirt is deposited on the same, it is possible to remove these andachieve a reliable state of conduction.

Further, the socket 710 of the 19th embodiment is provided with aseparate means for creating the wiping effect. That is, as shown in FIG.64, when the IC package 1 is inserted in an accommodating space of thesocket 710, the IC package 1 seldom is placed accurately at the centerof the accommodating space. When all the four sliders 713 are moved fromthe open position to the pressing position shown in FIG. 60, the ICpackage 1 is positioned accurately at the center of the accommodatingspace. Accordingly, while moving the sliders 713 from the open positionto the pressing position, the side surfaces of the substrate 2 of the ICpackage 1 are pressed by the sliders 713 and move slightly. This createsa relative displacement of position between the contact portions 715c ofthe contact pins 715 and the terminals 4 of the IC package 1, so awiping effect is caused.

After the slider 713 moves to the pressing position shown in FIG. 60 inthis way, the jig 716 is pulled upward. This ends the work for mountingthe IC package 1. In this mounted state, the sliders 713 are biased tothe left in FIG. 60 due to the second spring portions 715e, but theforce defining the position caused by the first spring portions 715dengaged with the inclined portions 713b of the sliders 713 is stronger,so in normal conditions there will be no movement to the left in thefigure, that is, to the open position.

Next, an explanation will be made of the case of taking out the ICpackage 1 from the mounted state shown in FIG. 60.

For taking out the IC package 1, use is made of the pull-out jig 717shown in FIG. 63. If the guide pins 717a are pressed down manually or byan automatic machine guided by the guide cylinders 712, the actuatingpins 717b will press the shafts 714 and move the shafts 714 to theoutside of the horizontal direction. Accordingly, the sliders 713 aremoved to the left in FIG. 60. The second spring portions 715e follow theengagement portions 713c until the neutral position shown in FIG. 66.After this, the first spring portions 715d rise along the inclinedportions 713b and push up the step portions 713a so the contact portions715c separate from the substrate 2 and give the state shown in FIG. 65.From this state, the engagement portions 713c press the abuttingportions 715f and cause the contact portions 715c to re:tract from theregion where the IC package is mounted while giving tension to thesecond spring portions 715e. After the sliders 713 reach the openposition shown in FIG. 64, the jig 717 is pushed up from the ICsocket 1. Next, the position of the slider 713 is held by the bias forceof the first spring portions 715d downward. Accordingly, the IC package1 can be taken out by hand or by automatic machine.

As explained above, in the 19th embodiment, the IC package 1 is grippedby the contact portions 715c and extension portions 715h of the contactpins 715 at the time of mounting of the IC package 1, so when theterminals 4 of the IC package 1 extend from the top surface of thesubstrate 2 through the side surface to the bottom, the tips of theextension portions 715 may be made to contact the terminals 4 at thebottom surface of the substrate 2 of the IC package 1. Accordingly, thesocket 710 of the 19th embodiment may be applied to any type of ICpackage of the surface mounting type. Alternatively, as shown in FIG.68, the bottom surface of the IC package may be received by the baseportion 712f provided at the base plate 712. Further, the contact pins715 may be constituted by two independent portions, that is, firstcontact pins having the external connection terminals 715b, the firstspring portions 715d, the second spring portions 715e, and the contactportions 715 and second contact pins having the external connectionterminals 715b and the extension portions 715h. Further, in the 19thembodiment, the sliders 713 are supported by only the contact pins 715,but it is also possible to remove the extension portions 715h and havethe bottom surfaces of the sliders 713 contact the base plate 712.Further, there is no need to provide a large clearance as illustratedbetween the engagement portions 713c of the sliders 713 and the abuttingportions 715f and 715g of the contact pins 715. Further, therelationship of engagement may be made one in which the engagementportions 713c are made recesses and parts of the contact pins 715 enterin them. Further, in the 19th embodiment, all of the contact pins 715 inthe rows are separated from each other by ribs, but it is possible toform an insulating layer on part of the side surface of the contact pinsand provide ribs for every certain number of contact pins or eliminatethem all together. However, in this case, the sliders 713 can move inthe horizontal direction, but are preferably made to not be able to movein the axial direction, that is, the longitudinal direction, byproviding bearing portions for the shafts 714.

Next, an explanation will be made of a 20th embodiment of an IC socketassembly according to the present invention using FIG. 69 to FIG. 74

In FIG. 69, the substrate 2 of the IC package 1 has a rectangularconfiguration. Terminals (lands or pads) are arranged along the foursides of the same, but illustration of these is omitted. The socket bodyof the IC socket 810 and the base plate 812 also have rectangularconfigurations. The configurations along the four sides are the same.The base plate 812 is comprised of a plastic. At the four corners of thebase plate 812 are implanted shafts 812a with cuts in three directions.Some IC packages have terminals arranged only at two opposite sides.When using an IC socket exclusively for such IC packages, it issufficient to provide the configuration explained below at just the twoopposite sides.

The base plate 812 is provided with elongated grooves 812b as will beunderstood from FIG. 71, FIG. 73, and FIG. 74. At the top surfaces areformed ribs 812c sandwiching the elongated grooves 812b at the oppositesides. The ribs 812c are also formed at the side surfaces of theelongated grooves 812b or at the side surfaces of the base plate 812.Further, there are one more of these sets of ribs 812c than the numberof contact pins, explained later. These are arranged in parallel atpredetermined intervals from each other along the side surfaces of thebase plate 812.

Plastic actuation shaft members 813 are attached through the laterexplained plurality of contact pins to the base plate 812. Bearingportions may be provided at the base plate 812. At the opposite ends ofthe actuation shaft members are provided arms 813a. Further, twoprojections 813b and 813c are provided at the peripheral surfaces, whichconstitute the engagement portions. The recesses formed between the sameare made able to engage with the contact pins so as to move the contactpins as mentioned later. Further, the actuation shaft member s813 haveformed at part of their vicinity a number of ribs 813d one greater thanthe number of contact pins along the axial direction.

The contact pins 814 are press-fit so that the mounting portions 814aenter between the adjoining ribs 812c provided at the side surfaces ofthe elongated grooves 812b and thereby are attached to the base plate812. Each contact pin 814 has a base portion 814A, one end of the baseportion 814A having formed on it a contact portion 814c for pressing thesubstrate 2 of the IC package 1 from above and contacting with a notshown terminal and the other end of the base portion 814A having formedon it an external connection terminal 814b for connection to the printedcircuit board. Further, each of the the contact pins 814 has a firstspring portion 814d and second spring portion 814e constituting an armformed continuously with the base portion 814A. The second springportion 814e biases the contact portion 814c in the downward direction.Further, the extension portion 814f extending from between the externalconnection terminal 814b and the contact portion 814c contacts anactuation shaft member 813 from below. The tip comes in contact with thebottom of the substrate 2 in FIG. 71 to support the IC package 1.

Further, a projection 814g serving as an engagement portion is formedbetween the contact portion 814c and the first spring portion 814d andcan engage at the recess between the projections 813b and 813c formed asthe engagement portions of the actuation shaft member 813. In thisembodiment, a plurality of contact pins with such a configuration areprovided between the adjoining ribs 812c provided on the base plate 812and between the adjoining ribs 813d provided on the actuation shaftmembers 813 and attach the actuation shaft members 813 rotatably to thebase plate 812.

As will be understood from FIG. 70, the cover 815 has through holes 815aconnecting the large diameter portion and small diameter portion. Bypress-fitting the shafts 812a from the small diameter portion throughthe cover, they are attached to be movable vertically at the base plate812. Further, the cover 815 is provided with operating portions 815b forpressing the arms 813a and turning the actuation shaft members 813. Theactuation shaft members 813, further, have wound around them coilsprings 816 with one ends supported at the base plate 812 and the otherends at the actuation shaft members 813, which bias the actuation shaftmembers 813 in FIG. 71 to turn in the clockwise direction. In FIG. 70,the state is shown where the cover 815 is pressed down against the forceof the coil springs 816.

Next, an explanation will be given of the operation for mounting the ICpackage 1 in this embodiment. FIG. 74 shows the open state where the ICpackage can be attached and detached. This open state is the state whereby pressing down the cover 815 and using the operating portions 815b topress the arms 813a, the actuation shaft members 813 are turned againstthe force of the coil springs 816. At this time, the projections 814g ofthe first spring portions 814d of the contact pins 814 are pushed in theleft direction by the projections 813b and are pushed upward at the rootportion of the projections 813b, that is, the bottom of the recessesformed between the projections 813b and 813c. Accordingly, the contactportions 814c are retracted to a position enabling attachment anddetachment of the IC package 1.

To place the IC package 1 in the mounted state from this state, it issufficient to release the pressing force of the cover 815. Due to this,the actuation shaft members 813 turn in the clockwise direction due tothe restoration force of the coil springs 816 and first spring portions814d of the contact pins and the projections 813b of the actuation shaftmembers move in the bottom right direction. In this process, the secondspring portions 814e move the projections 814g in the downwarddirection. When the first spring portions 814d reach the substantiallyneutral position where the elasticity is lost, the contact portions 814creach the terminal surface, not shown, provided on the substrate 2 ofthe IC package 1 and come into contact with the terminal surface due tothe action of the second spring portions 814e.

The actuation shaft members 813 turn further clockwise from this state.By this, next, the projections 813c engage with the projections 814g andthe first spring portions 814d are tensed and pushed in the oppositedirection from the neutral position. Accordingly, in the process, thecontact portions 814c slide on the terminal surface of the substrate 2.If an oxide film is formed or dirt is adhered, this is rubbed off,thereby improving the conductivity. This action is usually referred toas wiping. The projections 813b engage with the side surface of thesubstrate 2 to result in the state of mounting shown in FIG. 71.

However, when placing the IC package 1 on the extension portions 814f ofthe contact pins 814 as shown in FIG. 74, the IC package 1 never isplaced at the ideal position. Therefore, when the projections 813b areengaged with the side surfaces of the substrate 2, one of the actuationshaft members positioned at the four sides of the IC socket will pressagainst the IC package 1. Accordingly, the projections 813b willrestrict the position of the IC package 1 in the horizontal directionand at the same time contribute to the wiping.

When replacing the IC package from the state of FIG. 71, it issufficient to press the cover 815. In this case, in an action oppositeto the above explanation, the projections 814g first follow theprojections 813c to the center positions of the first spring portions814d. After this, due to engagement by the projections 813b, the firstspring portions 814d are tensed and moved to the top left to reach theposition of FIG. 74. The IC package 1 is taken from the accommodatingspace to the outside from this state by hand or using some device. Whennot mounting a next IC package, if the force pressing on the cover 815is released, the arms 813a turn further from the position of FIG. 71 andstop at the position obstructed by the operating portions 815b.

In the 20th embodiment, a cover 815 was provided, but as will beunderstood from FIG. 71, the existence of the cover 815 considerablyenlarges the height dimension of the IC socket 810 as a whole. Thiscauses considerable loss space-wise when a plurality of printed circuitboards with the IC sockets 810 connected are superposed in variousdevices. Therefore, it is possible to remove the cover 815. In thiscase, it is sufficient to provide a suppressing means for restrictingthe rotation of the actuation shaft members 813 by the coil springs 816at the base plate 812 so that the angular position of the arms 813a inFIG. 71 becomes preferably less than 30 degrees. Accordingly, in thiscase, the IC package can be attached and detached using a correspondingjig without depending on the cover 815.

Further, if the distance in the horizontal direction from the positionof contact of the operating portions 815b of the cover with the arms813a to the centers of rotation of the actuation shaft members 813 islengthened, the force pressing down the cover 815 can be made smallerdue to the lever principle. Further, in the 20th embodiment, theposition of contact of the operating portions 815b of the cover with thearms 813a is in the upward direction of the position where the topsurface of the base plate 812 and the contact pins 814 contact and onthe plane parallel to the plane orthogonal to the top surface of thebase plate 812, so the cover 815 is guided by the shafts 812a and if thetop surface of the base plate 812 is pressed down vertically, thecontact pins 814 will be subjected to only a force pressing the topsurface of the base plate 812 orthogonally. There is no force in anyother direction. Therefore, compared with disposing the position ofcontact of the operating portion 815b of the cover with the arms 813elsewhere, the strength of the base plate 12 and the force supportingthe contact pins 814 do not need to be that great and the base plate 812can be made thinner. In particular, at the portion of the bottom of theelongated grooves 812b, the base plate 812 is thinner and the strengthis lower, so it is preferable to set the position of contact between theoperating portions 815b of the cover and the arms 813a as shown in the20th embodiment.

Further, in the 20th embodiment, the actuation shaft members 813 areprovided with a large number of ribs 813d one greater than the number ofcontact pins 814, but it is also possible to form an insulating coatingon part of the side surfaces of the contact pins 814 etc. and provideribs 813d for every certain number of contact pins 814 and sometimeseven to completely eliminate them. In these cases, however, bearings forthe actuation shaft members 813 are necessary at the base plate 812.Further, the contact pins 814 may be constituted by two independentparts, i.e., first contact pins having external connection terminals814b, first spring portions 814d, second spring portions 814e, andcontact portions 814c and second contact pins having external connectionterminals 814b and extension portions 814f.

Further, in the 20th embodiment, the IC package 1 is sandwiched betweenthe contact pins 814c and the tips of the extension portions 814f, sothe embodiment can be used even in cases where there is a terminalsurface on the bottom of the IC package 1 or where the terminal surfaceis made the bottom side for mounting, it is possible to apply theembodiment to IC packages with both sides as conduction planes ofcourse, and it is possible apply the embodiment to all types of ICpackages of the surface mounting type. The wiping by the tips of theextension portions 814f in this case is performed by having theprojection 813c of the actuation shaft members 813c mentioned above movethe IC package 1 in the horizontal direction. The present invention,however, is not limited to this configuration. The IC package 1 may besandwiched between the base portion 812e and contact portions 814cprovided on the base plate 812 as shown in FIG. 75. Further, in the 20thembodiment, the contact pins 814 are provided with first spring portions814d and second spring portions 814e differing in directions of bias,but it is also possible to form a single spring portion for causing abias force in the substantially bottom right direction in FIG. 71.

Next, an explanation will be made of the IC socket according to a 21stembodiment of the present invention using FIG. 76 and FIG. 77. FIG. 76is a cross-sectional view showing the open state where the IC packagecan be detached in the same way as FIG. 74 used for explaining the 20thembodiment. FIG. 77 is a cross-sectional view showing the state ofcompletion of mounting of the IC package in the same way as FIG. 71. Inthese figures, constituent elements similar to those of the 20thembodiment are given the same references. According, explanations of theconfiguration of the same will be omitted.

The point of difference from the 20th embodiment in the 21st embodimentis that the engagement portions formed between the actuation shaftmembers 813 and contact pins 814 are formed in a reverse relationship.That is, the actuation shaft members 813 are provided with singleprojections 813e and the contact pins are provided with two projections814h and 814i. The relationships of convexity and concavity arereversed.

As shown in FIG. 76, when the IC package 810 is in the open state, theprojections 814i of the first spring portions 814d of the contact pins814 are pressed by the projections 813e in the counterclockwisedirection and the projections 814h are pressed upward by the peripheralsurface of the actuation shaft members 813. In this state, the pressingforce of the cover 815 is released. If the actuation shaft members 813are turned in the clockwise direction, the projections 814i follow thesame while engaged with the projections 813e. Further, the contactportions 814c contact the terminal surface provided on the substrate 2of the IC package 1 at substantially the neutral position of elasticityof the first spring portions 814d. The actuation shaft members 813 turnfurther in the clockwise direction from this state. Due to this, theprojections 813e engage with the projections 814h and the first springportions 814d press the projections 814h while being tensed.Accordingly, the above-mentioned wiping is performed, then the state ofFIG. 77 is reached and the motion stops and the contact portions 814care pressed against the IC package 1 by the action of the second springportions 814e.

In the completed state of mounting of the IC package shown in FIG. 77,the arms 813a are positioned to block rotation by the operating portions815b, but this would never occur. Accordingly, in the case of thisembodiment, it is best that the position where the ribs 813d engage withthe side surfaces of the substrate 2 be made the position of completionof mounting, but it is not particularly necessary to do this. It is alsopossible to provide a restraining means on the base plate 812 asmentioned above. Further, the operation at the time of replacing an ICpackage is performed by pressing down the cover 815, but as will beunderstood from the explanation of the 20th embodiment, this operationis performed in the reverse order as the case of the mounting operationand therefore an explanation will be omitted. Further, theconfigurations and actions other than those explained above for the 21stembodiment are similar to those of the 20th embodiment.

As explained above, in the 20th and 21st embodiments, one of theengagement portions of the actuation shaft members and the contact pinswas made convex and the other made concave and engagement was made to beperformed twice in succession by rotation of the actuation shaft membersin one direction, so with one engagement the contact portions willdetach from the IC package and with the other engagement wiping will beperformed by the contact portions. Accordingly, it is possible to mountan IC package in a state with a good conduction.

I claim:
 1. A socket assembly for accommodating an electrical componenthaving a generally rectangular configuration and for electricallyconnecting a plurality of terminals arranged forming a row in parallelalong each of at least opposite sides of said electrical component to aprinted circuit board, comprising:a socket body having a generallyrectangular configuration; a plurality of flat plate-like contact pinswhich are arranged forming a row in parallel along each of at leastopposite sides of said socket body, each of said contact pins having abase portion and an arm which extends curved upward from said baseportion, each said base portion having at one end thereof an upwardcontact portion for contact to one of said terminals of said electricalcomponent and at the other end thereof a connecting portion forconnection to said printed circuit board; and a plurality of sliderseach of which is supported by said base portions and said arms of saidcontact pins in said row and is movable between an open position atwhich said electrical component can be loaded onto or unloaded from saidcontact portions of said contact pins in a direction perpendicular tothe moving direction of said slider and a pressing position at whichsaid slider is pressed against said electrical component by an elasticforce of each of said arms so as to bring the terminals of saidelectrical component into press-contact with said contact portions ofsaid contact pins in the row of said contact pins.
 2. A socket assemblyas set forth in claim 1, wherein said slider has an upper pressingportion for pressing against an upper surface of said electricalcomponent and a lower abutment portion for pressing against a sidesurface of said electrical component.
 3. A socket assembly as set forthin claim 1, wherein said slider has an upper surface for coming intosliding contact with said arms in said row of said contact pins and alower surface for coming into sliding contact with said base portions insaid row of said contact pins, and a plurality of ribs slidably fittedbetween said arms and said base portions in said row of said contactpins are formed on the upper surface and lower surface of said slider soas to form a row.
 4. A socket assembly as set forth in claim 1, whereineach of said sliders has opposite end portions projecting longitudinallyoutward beyond said row of said contact pins and being engageable with ajig for moving each of said sliders between said open position and saidpressing position, and wherein said socket body has a jig guide meansfor guiding said jig in a vertical direction perpendicular to themovement direction of said slider.
 5. A socket assembly as set forth inclaim 4, wherein said jig guide means has guide holes formed at fourcorners of said socket body and guide groove holes which adjoin saidguide holes and are formed along opposite ends of the respective rows ofsaid contact pins; pins positioned above said guide groove holes areprovided on opposite ends of said sliders; said jig has guide posts forinsertion into said guide holes and leg portions for insertion into saidguide groove holes; and inward or outward inclined surfaces are formedat respective tips of said leg portions.
 6. A socket assembly as setforth in claim 1, wherein a plurality of ribs respectively fittedbetween said base portions in said row of said contact pins are formedon said at least opposite sides of said socket body.
 7. A socketassembly as set forth in claim 1 or 6, wherein engagement groovesextending along the row of said contact pins are formed on said at leastopposite sides of said socket body, and projection portions forengagement with said engagement grooves are formed on said base portionsof said row-forming contact pins.
 8. A socket assembly for accommodatingan electrical component having a plurality of terminals and forelectrically connecting the electrical component to a printed circuitboard, comprising:a socket body; a plurality of contact pins which areimplanted on said socket body and arranged forming a row in parallelalong at least one side of said socket body, each of said contact pinshaving a base portion and a contact portion formed at one end of saidbase portion for contact with one of said terminals of said electricalcomponent; a slider which is arranged along at least one side of saidsocket body and movable between an open position at which saidelectrical component can be loaded onto or unloaded from said contactportions of said contact pins in a direction perpendicular to the movingdirection of said slider and a pressing position at which said slidercan press against said electrical component to bring the terminals ofsaid electrical component into press-contact with said contact portionsof said contact pins; and a spring means which is arranged along atleast one side of said socket body and gives a pressing force withrespect to said electrical component to said slider, wherein each ofsaid contact pins has a bent portion projected to one side of of saidbase portion, and said slider has a pressing portion for pressingagainst an upper surface of said electrical component and a plurality ofengagement members engageable with said bent portions of said contactpins, and wherein said engagement members are adapted to pass said bentportions of said contact pins while resiliently displacing said contactpins laterally during a period when the pressing portion of said sliderfurther advances along the upper surface of the electrical componentafter reaching the upper surface of the electrical component from theopen position at which it retracts from the upper surface of theelectrical component and thereby to rub each of said contact portions ofsaid contact pins with one of said terminals of said electricalcomponent.
 9. A socket assembly as set forth in claim 8, wherein saidengagement members of said slider are arranged on both side surfaces ofsaid contact pins.
 10. A socket assembly as set forth in claim 8,wherein bent portions of said contact pins are alternately projected inopposing directions in an order of arrangement of said contact pins. 11.A socket assembly as set forth in claim 8, wherein each of said contactpins is provided with a support portion extending downward from saidbase portion between said contact portion and said bent portion andhaving a lower end portion supported by said socket body.